Warren Gatland
Gatland has less than a month to formulate his plans for the three-test series against New Zealand.Getty Images

The Six Nations are done and dusted for another year and without delay all eyes turn to the British and Irish Lions tour to New Zealand in the summer. While England claimed the northern hemisphere's annual title, they were denied the Grand Slam by Ireland and every nation, aside from Italy, had cause for optimism. And a large pool of players have reason for hope when it comes to Lions selection.

The special nature and rivalries of the Six Nations tournament somehow levels the playing field between the northern hemisphere elite and brings out the best in players. But what Lions coach Warren Gatland must decide is which of those individuals will be able to stand up to what is probably rugby's ultimate test: a tour of New Zealand, winners of the last two World Cups.

England won the Six Nations and thus theoretically have the best players, but the way that the Irish disrupted and dominated at the Aviva Stadium could yet see a shake-up in selection. Indeed, the Irish players now have a much better record when it comes to halting juggernauts: for Ireland have now, in a matter of months, stopped New Zealand and ended England's hopes of claiming the world record for consecutive test victories. But will Ireland's players be able to continue their role as spoilers when playing on the All Blacks' home turf?

Coach Gatland spent much of the weekend being interviewed about his Lions plans and revealed that he has 20-25 players already pencilled in and has just a handful of decisions still to make before the squad is announced on 19 April.

Predicting Gatland's squad might be slightly easier than picking his starting XV, as the final line-up will depend upon how he balances his resources, and whether he chooses players on form or in partnerships, and, indeed, what style of rugby he hopes to play. For instance centre Jonathan Joseph scored a hat-trick of tries against Scotland, when England ran rampant, but was a much more subdued figure when starved of the ball in Dublin. Will Gatland pick a midfield for attack or defence?

Dylan Hartley
Will Dylan Hartley's disciplinary history count against him when it comes to Lions selection?Getty Images

So here are the contenders for that first test at Eden Park on 24 June, including a likely starting XV.

FORWARDS

FRONT ROW

One of the most intriguing selection questions is at hooker: Will Gatland pick Dylan Hartley, England captain and an experienced campaigner, but also a man who missed the last Lions tour after being suspended ahead of the trip to Australia for abusing a referee? This is far from the only blemish on Hartley's copybook. The alternatives are strong: Ireland's Rory Best and Wales' Ken Owens could play at number two. Indeed, Gatland, in his earlier role as Wales coach was a fan of Owens, whilst often using him as an impact sub rather than a starter.

At loosehead prop, Wales' Rob Evans had an outstanding Six Nations tournament, but will face competition from England's Joe Marler and Mako Vunipola and his skills in the loose. Tighthead prop could come down to a choice between England's Dan Cole and Ireland's Tadhg Furlong.

SECOND ROW

Alun Wyn Jones was another Welshman who always gives his all, even when Wales' Six Nations ambitions were falling short of their ambitions. He is admired for his decision making and work rate, which in the game against Ireland featured 14 ball carries and 18 tackles. Meanwhile, even as England were hammering Scotland, Joe Launchbury was showing his worth with 22 tackles.

Alun Wyn Jones
Jones captained the Lions for the third test in Australia and is a strong contender to return as skipper.Getty Images

Another Englishman, George Kruis, did not get the chance to press his Lions claims during the Six Nations due to injury, but he will be in contention, as will Maro Itoje, who played a full part. Scotland's Jonny Gray and Ireland's versatile Iain Henderson should also make the squad, particularly as both are locks who can play in the back row if necessary.

BACK ROW

Freed of the constraints of captaincy, Sam Warburton had another excellent Six Nations but has also been a victim of Wales' tinkering in the back row to accommodate the lineout strength of Justin Tipuric, who may also secure a place on the Lions tour.

Ireland's back row did their Lions chances little harm with their standout performance in front of Gatland in Dublin. South African-born CJ Stander was outstanding at number eight, as was Peter O'Mahony, who was only drafted into the starting line up at flanker after Jamie Heaslip was ruled out with a hamstring injury. The disruption that this pair caused to England in the grand slam decider could be key for the Lions in New Zealand.

Peter O'Mahony
O'Mahony was a revelation for Ireland in the back row.Getty Images

England offer other back row alternatives, particularly Fiji-born Nathan Hughes and Australian-born Billy Vunipola.

BACKS

HALF BACKS

Could Gatland be tempted to select his half-backs as a pair rather than as two individuals? In which case Ireland's scrum half Conor Murray and fly half Johnny Sexton will have a very strong case. Murray's box kicking put teams under constant pressure, while Sexton's all-round kicking game and experience count heavily in his favour.

England may have won the Six Nations title but with a frequently shifting half-back pairing, starting games with Ben Youngs and George Ford, but this pair usually making way for Danny Care and Owen Farrell for the closing stages of games. Another partnership who may come in for consideration are Rhys Webb and Dan Biggar, although Wales' fluctuating championship fortunes may count against them.

Johnny Sexton
Sexton's accuracy kicking out-of-hand could challenge New Zealand's aerial prowess.Getty Images

CENTRES

England's centre partnership of Farrell and Joseph had some spectacular days during the tournament, but the former is a converted number 10, picked out of position primarily to accommodate his goal-kicking and ferocious defence, while Joseph looks great against lesser opposition, but would he be found out by the Kiwis? Both may win squad places and Farrell may even be switched back to fly-half, but neither are definite starters for the brutality of a test match against the free-flowing All Blacks.

Wales' Jonathan Davies and Ireland's Robbie Henshaw are in contention for centre, although England's Elliot Daly is another option, not least for his electric speed and goal-kicking ability. Could Ireland's Garry Ringrose be a longshot for a tour place, wearing the number 13 jersey not-so-long-ago adorned by Irish legend Brian O'Driscoll?

WINGS

How many of the three wings and full back positions will the Welsh fill? There is a strong case for George North and Liam Williams on the wings and Leigh Halfpenny at full back. Williams can also play at full back. Other wing options include Ireland's Simon Zebo as well as England's Anthony Watson and Jack Nowell.

Stuart Hogg
Hogg has quickly developed into one of the most feared players in the northern hemisphere.Getty Images

FULL BACK

Halfpenny was the Lions' Man of the Series in Australia four years ago, and while a little off his best on occasions this spring after recovering from a ruptured anterior cruciate knee ligament, he has the all-round game that could be invaluable in New Zealand. Halfpenny was third top scorer in the Six Nations, with 62 points, so his final selection may depend on which kicking options Gatland chooses elsewhere. Scotland's Stuart Hogg has surged into serious contention with five tries over the last two Six Nations.

This is a potential squad low on Scots but with a good balance between the other home nations. Gatland is already under pressure to name his skipper, but has indicated that the captain needs to be a test certainty and how many of those have already been chosen?

Ahead of the last game of the Six Nations Gatland was asked what was required on a Lions tour and replied: "It's not always about playing pretty rugby. It's what's up here and in here [pointing at head and heart]." The squad selected in April will very much be a reflection of both.

I've chosen my Lions XV, but what's yours? Please share your team on Twitter to @Busfield and @IBTimesUKSport.