Theresa May will continue to sell her Brexit withdrawal deal on Friday, as cabinet minister Michael Gove is understood to be considering quitting. BBC political editor Laura Kuenssberg said she understood Gove had rejected the PM's offer to make him Brexit secretary, because May would not let him renegotiate the deal. Dominic Raab quit the role on Thursday over "fatal flaws" in the agreement. May says the deal "delivers what people voted for". But she was warned by one of her own backbenchers that it was "dead on arrival" and would never get the backing of MPs. The government unveiled its long-awaited draft withdrawal agreement on Wednesday, which sets out the terms of the UK's departure from the EU, over 585 pages. The prime minister will answer callers' questions about the plan on LBC radio on Friday morning. Asked about Gove on Thursday, May said he was doing "an excellent job" as environment secretary, adding: "I haven't appointed a new Dexeu [Department for Exiting the European Union] secretary yet and I will be making appointments to the government in due course." But the BBC understands Gove, a leading figure in the Leave campaign during the EU referendum, rejected her offer to make him Brexit secretary, saying he would only accept it if he could try to make changes to the negotiated deal – something May has made clear is not possible. Gove is said to have been key to getting backing for May's deal at a lengthy cabinet meeting on Wednesday – during which a number of ministers expressed doubts. Former Brexit Secretary Dominic Raab and Work and Pensions Secretary Esther McVey both went on to quit over the agreement. The draft agreement has also upset some Tory backbenchers, including leading Brexiteer Jacob Rees-Mogg, who said he and others had submitted letters of no confidence in May to the chairman of the Conservatives' backbench 1922 Committee. Forty eight letters are needed to trigger a confidence vote. It is understood that a group of cabinet ministers are also considering whether to try to force May to make some changes to the withdrawal deal.   'Right for our country' The agreement sets out commitments over citizens' rights after Brexit, the proposed 21-month transition period, the £ 39 bn "divorce bill" and, most controversially, the "backstop" to avoid a hard border between Northern Ireland and the Republic of Ireland. It still needs to get the stamp of approval from MPs in Parliament, and finally from the 27 other EU member states. May issued a defiant message in Downing Street on Thursday, saying: "I believe with every fibre of my being that the course I have set out is the right one for our country and all our people." She added: "Leadership is about taking the right decisions, not the easy ones." She acknowledged some were not happy with the compromises made to secure the deal, but said it "delivers what people voted for and it is in the national interest". She also vowed to "see this through". But Labour Leader Jeremy Corbyn told her: "The government simply cannot put to Parliament this half-baked deal that both the Brexit secretary and his predecessor have rejected." And Liberal Democrat leader Sir Vince Cable suggested the PM was "in denial", adding she had "rightly conceded that 'no Brexit' is the real alternative".