LONDON (Reuters) - British Prime Minister Theresa May will face an immediate leadership challenge from eurosceptic lawmakers in her party if she seeks to water down her plans for Brexit, the Sunday Telegraph reported, citing senior Conservative sources.

Britain's Prime Minister, Theresa May, arrives in Downing Street in central London, Britain, June 14, 2017. REUTERS/Peter Nicholls

May, who won the top job in the wake of last year’s vote to leave the European Union, had in January set out her plans for Brexit, saying Britain would leave the single market so it could control immigration.

But May’s failure to win a majority in last week’s election has weakened her position badly and reopened the debate around the Brexit strategy just days before the country opens its divorce talks with Brussels on Monday.

Prompted by her poor election showing, particularly among pro-EU young people who fear losses of jobs and opportunity from Brexit, some of her most senior ministers and two former Conservative prime ministers have called for a rethink.

“If we had a strong signal that she were backsliding I think she would be in major difficulty,” the newspaper quoted one unidentified former minister as saying.

“The point is she is not a unifying figure any more. She has really hacked off the parliamentary party for obvious reasons. So I’m afraid to say there is no goodwill towards her.”

The newspaper quoted another former minister as saying: “If she weakened on Brexit, the world would fall in... all hell would break loose.”

May called the election in a bid to increase her majority and strengthen her hand within her party ahead of the Brexit talks.

But the unexpected weak performance has plunged Britain into a political crisis and left May battling to unite both wings of the Conservative Party - those who want a so-called “hard Brexit” and those who did not want to leave the EU in the first place.

The Sunday Times said ministers within May’s cabinet had ‘let it be known’ they would oust the prime minister if they thought she could not pass the government’s legislative program in a vote expected on June 28.

The Times also reported that party members who had campaigned to keep Britain in the EU were likely to have a candidate lined up to replace May, with interior minister Amber Rudd the likely option.

Having lost a majority in parliament, May is in talks with Northern Ireland’s Democratic Unionist Party to secure the support of its 10 lawmakers to win any kind of vote, including on the pieces of legislation needed to enact Britain’s divorce from the EU.

DUP leader Arlene Foster has said she wants a “sensible Brexit” that works for the United Kingdom and the Republic of Ireland.