BUSINESS leaders and senior Tories threw a lifeline to Theresa May yesterday as they lined up in favour of her Brexit deal.

But the embattled Prime Minister’s future still hung in the balance as backbenchers organised for a vote of no confidence.

Labour’s shadow chancellor John McDonnell warned that Ms May “will not command a majority” for the deal, which keeps Britain aligned with EU regulations on state aid, competition and public procurement until at least 2020 and possibly indefinitely.

The Confederation of British Industry (CBI) said that her agreement with the European Union (EU) was satisfactory and urged politicians to back it for the sake of national economic prosperity, while pro-Brexit Tories Liam Fox and Michael Gove urged rebellious backbenchers to support Ms May rather than risk an exit without a deal or one negotiated by Labour.

CBI director general Carolyn Fairbairn described the deal as “progress” and welcomed the extension of EU rules to 2020, saying the transition period took the country “one step away from the nightmare precipice of no deal” and that “securing a transition deal has long been firms’ top priority.”

The CBI also demanded that “frictionless trade, ambitious access for our world-beating services and a say over future rules” be sought from Brussels in the future.

The London Stock Exchange Group also rallied to the PM, saying: “We believe this agreement will support financial stability, reinforce global regulatory co-operation and reduce uncertainty for our customers around the world.”

Meanwhile, Stephen Jones of UK Finance, which represents bankers and others working in the sector, welcomed the deal as an “important step forward.”

Even drinks giant Diageo warned: “It is now vital for business confidence that Parliament votes in favour of this deal.”

Ms May received a boost from the German parliament’s foreign affairs committee, with Norbert Roettgen of Chancellor Angela Merkel’s right-wing ruling party warning of “geopolitical disaster” if the agreement fails to pass.

Following Thursday’s high-profile resignations of Brexit secretary Dominic Raab and work and pensions secretary Esther McVey, Ms May faced a tense time yesterday.

Conservative chief whip William Holmes cancelled all press briefings for MPs, while former Brexit minister Steve Baker claimed that the Tories’ 1922 Committee, which consists of all the party’s MPs, was “very close” to having the 48 votes of no confidence needed to remove Ms May and trigger a leadership election.

However, she plugged the gaps left by the resignation by recalling Amber Rudd to the Cabinet to run the Department for Work and Pensions and giving the Brexit brief to Stephen Barclay.

Ms Rudd resigned in disgrace earlier this year over the Windrush scandal, which saw black Britons wrongfully deported, while Mr Barclay was promoted from his previous post as a junior health minister.

Mr McDonnell said that if Ms May pushes the deal to Parliament and can’t get a majority to back it, the constitutional convention would be to invite the opposition to form a government.

Despite EU claims that the deal is non-negotiable, he insisted that Labour would be able to reopen talks and win a better Brexit.

Shadow Brexit secretary Keir Starmer said cross-party opposition could be rallied to avoid both Ms May’s agreement and a no-deal exit.

Across the labour movement, organisations such as pro-Jeremy Corbyn campaigning group Momentum and Young Labour have called on Labour MPs to reject Ms May’s deal and force a general election.

The stance contrasts with that of Remain campaigns such as the Our Future Our Choice group, which unveiled a new anti-Brexit battle bus for its bid to force a second referendum.

Communist Party general secretary Robert Griffiths said the “bogus Brexit demanded by May’s business advisory council looks doomed.

“Rather than an anti-people’s second vote, we need a left-led Labour government to negotiate a People’s Brexit,” he stressed.

The party meets for its biennial congress this weekend, and Mr Griffiths said delegates would discuss “how to win greater understanding of the reactionary class character of the EU and wider unity around the need for a Corbyn government that is free to enact a left-wing programme.”