Andy Burnham has warned of the “very real prospect” the In campaign will lose the EU referendum and repeated his criticism that Labour has been “too much Hampstead and not enough Hull” over the last two decades.

With EU polls tightening amid concerns Labour supporters are undecided or unsure of the party’s stance, the shadow Home Secretary stepped up his demand for Labour to do more to target its traditional voters.

“We have definitely been far too much Hampstead and not enough Hull in recent times and we need to change that. Here we are two weeks away from the very real prospect that Britain will vote for isolation,” he told BBC Two’s Newsnight.

Last night some commentators and members of the Leave campaign seized on Burnham’s interview as an apparent criticism of the Labour In campaign, which he quickly denied.

“Andy Burnham’s comments have been misreported,” said a spokesman for the Leigh MP.

“He was answering a question about Labour in general being ‘a coalition between Hamsptead and Hull’. He repeated his long-standing analysis that Labour in the last two decades has been too London-centric.”

Burnham also told Newsnight that a vote for Brexit would have a “profound effect on our national life”, and echoed fears about the future of the country, described by Tony Blair and other leading Labour figures, adding: “If this decision is taken, dominoes will start to fall. It won’t just be the EU that starts to break up, it will be Britain too.”

Burnham, who is seeking the Labour nomination for the new Manchester mayoral role, has struck an increasingly strident tone as he warned the party has to listen to voter concerns over issues such as immigration from the EU. This week he urged voters not to treat the EU referendum as a single-issue “protest vote” over immigration.