Three MPs quit from the UK’s ruling Conservative party on Wednesday over the government’s "disastrous handling" of Brexit.
The MPs are to join the Independent Group, an attempt to create a non-aligned movement opposed to the main parties’ approach towards leaving the EU on March 29.
In a letter to Prime Minister Theresa May, the three women criticised what they said was a lurch to the right and said the government’s handling of Brexit was the last straw.
“The Conservative party no longer reflects the values and beliefs we share with millions of people throughout the UK,” the letter by MPs Heidi Allen, Anna Soubry and Sarah Wollaston said.
In a letter to her constituents, Ms Soubry said it was "time to realign British politics and get back to the centre moderate ground".
Mrs May said she was saddened by their decision to leave the party.
“These are people who have given dedicated service to our party over many years and I thank them for it," she said.
"Of course, the UK's membership of the EU has been a source of disagreement in our party and our country for a long time. Ending that membership after four decades was never going to be easy.”
Ms Soubry has long been a lightning rod for discontent among hardline pro-Brexit supporters after consistently speaking against the government’s line in parliament.
She has appeared alongside Labour party members speaking out against the effects of Brexit on the UK economy.
The three are the first from the Conservative party to join the new political group, which could reshape UK politics.
Former Conservative prime minister John Major had urged disaffected MPs not to quit because it would leave the party in the hands of extremists and zealots, the Daily Mail reported.
Mr Major said both main parties were being "manipulated by fringe opinion".
The three join eight former opposition party members who left the Labour party this week, saying they were concerned with national security, bullying and institutionalised anti-semitism. They also criticised the party’s stance on Brexit.
Both parties have said that they will respect the outcome of the 2016 referendum in which 52 per cent of those who voted said they wanted to leave the EU.
But negotiations with the bloc over their future relationship have stalled, leading to the increasing likelihood of a clean break next month, ending decades of trading and political agreements.
The former Labour MPs announced their decision to quit on Monday with an eighth member announcing her departure late on Tuesday, sparking speculation that others would follow.
Joan Ryan quit with a broadside against the party’s failure to tackle anti-semitism.
“The other huge problem is that I think Jeremy Corbyn is aiding and abetting a hard Brexit," Ms Ryan said.
Britain's leadership is seeking new concessions from the EU that would allow the two sides to strike a last-minute deal little more than a month before the country is due to leave.
The defections further weaken Mrs May's attempts to strike a deal that would prevent border checks and allow for uninterrupted trade while the two sides negotiate a long-term political and economic agreement.
The EU has given few signs of willingness to concede on any points of a deal struck with Mrs May's negotiators late last year. That deal was later overwhelmingly rejected by MPs.
Meanwhile, late on Wednesday the Labour party announced that Derek Hatton, a former far-left party official whose readmission to the party on Monday caused uproar among moderates, was suspended only two days later.
Labour’s governing body said that a tweet sent by Mr Hatton in 2012, in which he urged “Jewish people with any sense of humanity” to condemn Israel’s “ruthless murdering”, had been brought to their attention and that his membership application had been suspended.
There were reports late on Wednesday night that Thursday woul see further defections from the Labour party, according to Ross Kempsell, political editor of TalkRadio: