Prime Minister Theresa May said she will not allow compromises to her Brexit strategy that go against the national interest, seeking to allay fears among some in her Conservative Party that she will cave in to Brussels' demands in negotiations.

But her words drew skepticism, including from the former Brexit negotiator, David Davis, who said the pledge was little reassurance and that he will vote against Parliament giving May's exit plan its required approval.

With under two months before Britain and the European Union want to agree a deal to end over 40 years of union, May is struggling to sell what she calls her business-friendly Brexit to her own party and across a divided country.