HEIDI Allen's criticism of the DUP in her farewell letter to Theresa May is not the first time she has voiced opposition to Arlene Foster's party.
In her correspondence yesterday, Ms Allen, Sarah Wollaston and Anna Soubry said they could not remain in the party of a government whose policies and priorities "are so firmly in the grip of the ERG and DUP".
The South Cambridgeshire MP has previously been critical of Mrs May's reliance on the DUP for support in key votes in the House of Commons.
In 2017, Ms Allen told of her "anger" at her party's £1 billion deal with the DUP and argued that the Conservatives should have formed a minority government instead.
I really don’t wish to be rude to Sammy (genuinely), but it does beg the question, why the heck did we pay £1bn for this! Hate to say I told you so..... https://t.co/oe8fZNGOrx
— Heidi Allen MP (@heidiallen75) October 11, 2018
She said she could "barely put into words my anger" at the deal, expressing her "distaste" for using taxpayers' funds to "garner political control".
Ms Allen also clashed with DUP MP Sammy Wilson in June last year during a debate on abortion.
She broke down after revealing her "incredibly hard decision" to have a termination as she spoke out during an emergency debate on extending abortion rights to women in Northern Ireland.
But just moments after her speech, Mr Wilson launched an angry tirade about UK abortion laws. Waving his finger at colleagues, including Ms Allen, he said he was "not embarrassed" about his pro-life stance.
Last October, Ms Allen and Mr Wilson clashed again when she voiced criticism of the East Antrim MP on social media.
It came after Mr Wilson warned his party would withdraw support from the government if it did not approve of the Brexit deal.
But Ms Allen hit back and tweeted a reference to the confidence-and-supply arrangement between the two parties and the £1bn deal that arrangement guarantees for Northern Ireland.
"I really don't wish to be rude to Sammy (genuinely), but it does beg the question, why the heck did we pay £1bn for this! Hate to say I told you so..."