Kempf said he only saw further uncertainty: "I appeal to the lawmakers in the British parliament to be conscious of their responsibility", he said.
By seeking to preserve the closest possible ties with the EU, May has upset her party's many advocates of a clean break, and Northern Ireland's Democratic Unionist Party (DUP), which props up her minority government.
By Sunday afternoon, a total of 25 MPs had revealed they had sent no-confidence letters to the chairman of the party's 1922 Committee, Sir Graham Brady.
Mrs May has been under intense pressure ever since the publication of the 585-page draft withdrawal agreement on Wednesday, with Brexit secretary Dominic Raab and Work and Pensions minister Esther McVey submitting their resignations the next day.
"If MPs (legislators) reject the deal, they will simply take us back to square one". "If you start trying to amend it or unthink it, you might find that the whole thing unravels". May's deal is bad for the country.
"The deal does not protect jobs or livelihoods of the people in the West Midlands".
Ireland's foreign minister, Simon Coveney, said on Saturday that British pro-Brexit ministers were "not living in the real world" if they thought they could renegotiate the divorce treaty agreed with the European Union last week.
He told Sky News there was support in parliament and in Europe for a "unity platform" that avoided a no-deal Brexit.
A significant number of Conservative MPs also intend to oppose the deal.
As British Prime Minister Theresa May fights to save her Brexit deal, former U.K. Parliament Member John Browne said embarking on a "hard Brexit" is suitable.
Several members of May's Cabinet have resigned over the disagreement with the deal. Labour's deputy leader Tom Watson has also said a second referendum, dubbed the People's Vote, should not be ruled out.
The prospect of this vote would throw the country into turmoil, with no clear idea about who would take over as Prime Minister. "If we change the person at the top, whoever is at the top we will still have the same problems".
May now faced the tough challenge of pushing her proposed deal through the House of Commons, the lower chamber of United Kingdom lawmaking.
Gosport MP Caroline Dinenage says that although she hasn't seen the full deal yet, she will also be backing Theresa May in the coming months.
"After two years of hard work, we are now arriving at what I firmly believe is the right deal for Britain ..."
The reshuffle came just hours after Michael Gove offered the Prime Minister a lifeline by staying on in his Cabinet role.
He told Sky News Sunday that his party will vote against the deal and demanded that May return to Brussels and renegotiate the divorce agreement. Parliament will not support no deal.
"What I think is this is not about me - it's about what's in the national interest".
"Everybody has to accept not they are not going to get everything they want out of it".
If 48 letters are eventually handed in, it will mean that 15 per cent of the party have chosen to opt for a new leader, triggering a reelection in which Mrs May will not be allowed to stand.
Asked about the actions of Tory Brexiteers, Ms James, who is digital minister said: "I think it's beneath contempt".
It is a "backstop we never intend to use", she said, adding: "Were it to have to be used, both sides can review it". "No deal would be catastrophic for the economy".
"There is no alternative plan on the table".