John Mann, the pro-Brexit Labour MP for Bassetlaw, has led negotiations with the government

Greg Clark is poised to make it easier for unions to strike as he steps up efforts to woo Labour MPs to back Theresa May’s Brexit deal.

Ministers have long resisted a union demand to allow ballots on industrial action by email or text, claiming that they risk being hacked.

Unions complain that requirements on postal ballots together with higher turnout thresholds introduced two years ago unfairly limit their capacity to win enough backing to call workers out on strike.

Labour MPs in talks with the government over their possible support for the Brexit deal say that Mr Clark, the business secretary, has promised he will introduce electronic balloting. Last night, the department for business, energy and industrial strategy (BEIS) confirmed that it was preparing