British Prime Minister David Cameron and Labour Party leader Jeremy Corbyn will make separate calls for Britain to remain in the EU on Saturday, 12 May, while campaigning for the June 23 EU referendum. With less than six weeks until the vote, the Remain and Leave camps are neck-and-neck with polls showing Britons are evenly split on which way to vote.

Data from a Sky News poll suggests that economy is not as important as immigration to voters who deciding whether the UK should stay or leave the EU. Out of the 29% of voters who the poll registered as "undecided", only 15% list the British economy as their greatest concern, while 28% are most concerned about the impact membership of the EU has on immigration.

David Cameron, Chancellor George Osborne and the Remain camp have focused their campaign on the economy. A Treasury report saying that leaving the EU could cost each household £4,300. The Bank of England's Mark Carney warned this week that Brexit could trigger a long recession.

The official Stronger in Europe campaign said that it will put on 1,000 events today, according to the BBC. Cameron is set to unveil a poster highlighting the negative economic impact of voting to leave the EU, which warns that leaving the EU could cost each household £4,300.

Leave campaigners are criticising the prime minister of "failing to be honest", arguing that EU membership, which costs £50m ($71.8m) per day is costing British taxpayer money.

"David Cameron knows that not a single British family would lose that amount of money if we Vote Leave. In fact, they would prosper as we spend our money on our priorities," Vote Leave chief executive Matthew Elliott told the BBC.

Although both Cameron and Corbyn both represent the Remain vote, Labour Party leader Jeremy Corbyn will argue that the country's Conservative government – not the EU – is to blame for the "many problems" in the UK, telling people responsibility for the country's problem "lies in 10 Downing Street, not in Brussels".

EU vote split

Conservative cabinet minister Owen Paterson and Ukip migration spokesman Steven Woolfe on the Vote Leave camp say an EU exit is an opportunity "to take back control of Britain's destiny". Paterson argues that leaving the EU will help Britain "take back control of our own affairs," while a vote to stay would result in the UK becoming "a colony of an EU superstate, with more integration and increasingly diminished British influence".

Ex-London mayor Boris Johnson is also expected to make a speech supporting a vote for Britain to leave the EU. Vote Leave is expecting him to speech in Bristol to embellish "the positive vision for Brexit".

The referendum campaign is gaining momentum after regional and local elections last Thursday which saw Labour party's Sadiq Khan being elected as London mayor and the SNP returning to power in Scotland, though without a majority.

The majority of undecided voters are young people (18-24 year-olds), while more women than men are left to make up their minds, according to Sky News.

A poll-of-polls made for by NatCen Social Research, based on the polls taken between 26 April and 8 May, shows the Remain and Leave vote even split at 50% each.