LONDON (Reuters) - British Prime Minister Theresa May says she sees no alternative to the Brexit deal she presented earlier this week, amid reports that some of her senior ministers want her to renegotiate the draft agreement before meeting EU leaders next weekend.

Britain's Prime Minister Theresa May leaves 10 Downing Street via the back exit in London, Britain, November 16, 2018. REUTERS/Peter Nicholls

“There is no alternative plan on the table. There is no different approach that we could agree with the EU,” May wrote in an article for the Sun on Sunday newspaper.

“If MPs (legislators) reject the deal, they will simply take us back to square one. It would mean more division, more uncertainty and a failure to deliver on the vote of the British people,” she added.

Just hours after announcing on Wednesday that her senior ministers had collectively backed her divorce deal, May was thrust into her premiership’s most perilous crisis when Brexit Secretary Dominic Raab resigned on Thursday to oppose the agreement.

Other mutinous lawmakers in her party have openly spoken of ousting her and said the Brexit deal would not pass parliament.

Brexit supporters say the transitional deal risks leaving Britain subject to EU rules for an indefinite period.

On Saturday Andrea Leadsom, the minister in charge of government business in parliament, told the BBC that she was supporting May but was not fully happy with the deal.

“I think there’s still the potential to improve on the clarification and on some of the measures within it and that’s what I’m hoping to be able to help with,” she said.

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 EU last week.

Several British newspapers had reported that Leadsom was working with four other senior ministers and Brexit enthusiasts - Michael Gove, Liam Fox, Chris Grayling and Penny Mordaunt - to pressure May to change the deal.

Mordaunt, Raab, and five other top Conservatives - former Foreign Secretary Boris Johnson, Raab’s predecessor David Davis, Interior Minister Sajid Javid, Foreign Secretary Jeremy Hunt, and Work and Pensions Minister Amber Rudd - are all “actively preparing” leadership campaigns, the Sunday Times said.

More than 20 Conservative lawmakers have written to call for May to go, and a total 48 requests are needed to trigger a leadership contest.

The Sunday Times also reported Britain’s army had been ordered to step up contingency plans to help police maintain public order in case of food and medicine shortages after a “no deal” Brexit, citing an unnamed “well-placed army source.”