Tottenham Hotspur manager Mauricio Pochettino has sent the strongest message yet to chairman Daniel Levy over the club's business in the summer transfer window and is demanding new faces to continue their push towards the Premier League title. The north Londoners are the only side in English football's top four divisions not to have added to their squad ahead of the new campaign which is just a fortnight away.

Spurs have been heavily linked with a move for Everton playmaker Ross Barkley but appear no closer to securing a deal for the wantaway England international who is "100%" likely to leave Goodison Park this summer according to manager Ronald Koeman. An offer of between £30m-£35m would be enough to sign Barkley but Tottenham are only willing to pay £20m.

However, while speculation regarding other additions have been few and far between, their rivals including Manchester City, Manchester United and Liverpool are threatening to leave them for dust.

Pochettino has already admitted Tottenham are behind their rivals ahead of the new campaign, which starts against newly-promoted Newcastle United on 13 August.

And the Argentine boss has delivered another warning to the club's hierarchy - who have denied the move into their new stadium is prohibiting their operations in the transfer market - that their best players need competition if they are to improve.

"How have Manchester City, Liverpool, Chelsea and different clubs tried to improve their season?" the Tottenham boss said, according to The Guardian. "Bringing players and trying to put more pressure on their star players, their key players - and for us we need to do that too.

"Right, now [I hear] we need to win some trophies, no? That is good, the pressure. I think it's important to understand now that we need to be clever how we manage the expectation and how we need to put pressure on our own players.

"We understand that Dele Alli, Harry Kane, Christian Eriksen, (Eric) Dier, (Toby) Alderweireld are really good players. They want to win but need to feel the pressure a little bit to improve every season. If there's no competition in behind it's normal to drop your motivation, it's normal to drop everything that you do. And then it's difficult to win."

Though Kyle Walker has joined City in a record deal for an English player, Tottenham's main victory this summer has been keeping hold of their prized assets. Eric Dier has been prevented from joining United, while Kane and Alli remain the cornerstone of a side who will hope to go one better than their second place finish behind champions Chelsea last term.

Nevertheless, the difference between the business conducted by Tottenham and their rivals has been striking. City have made five major signings including Bernardo Silva from Ligue 1 champions Monaco; United have acquired Romelu Lukaku in a deal which could rise to £100m; Arsenal have brought in France's Alexandre Lacazette while Liverpool have built on achieving Champions League qualification by signing Mohamed Salah from Roma.

Chelsea meanwhile have secured the services of Alvaro Morata and Tiemoue Bakayoko in an otherwise low-key summer. Pochettino will be concerned that having failed to address the lack of depth which eventually undid their title bid and saw them crash out of the Champions League at the group stage, any injuries could lead to them relinquishing their place in the top four.

Mauricio Pochettino
Pochettino has again warned Tottenham could lose ground on their rivals. Getty Images