John Mann was one of seven Labour MPs to back the government over Brexit. He is said to be in negotiations to secure cash for his constituency FACUNDO ARRIZABALAGA/EPA

Theresa May is preparing to entice Labour MPs to support her Brexit deal with a cash injection into deprived areas that supported Leave, including former mining communities.

The prime minister’s allies believe that she needs the backing of about 20 Labour MPs for a modified agreement to offset the number of Tory rebels, even if she wins the support of the DUP.

Potential Labour backers are now being wooed with the promise of local investment as Downing Street increases efforts to build a parliamentary majority before a second vote.

“There’s a willingness to look again at coalfield communities and make good the promises that former Labour governments failed to deliver,” a well-placed government source said. “It’s about allowing Labour MPs representing Brexit communities to show…