LONDON, Jan. 14 (Xinhua) -- British Prime Minister Theresa May said Monday she was against delaying Britain's exit from the European Union, insisting the March 29 departure date was still her target.

Speaking at a factory in middle England's potteries region, May also said she opposed a second referendum.

She announced she would close the debate Tuesday night ahead of what is seen as the most crucial vote in the House of Commons since the end of World War II.

In what was her last public speech ahead of Tuesday's crucial vote by MPs in the House of Commons, May said if politicians reject Brexit it will be the first time Westminster has rejected the result of a public referendum in Britain.

She warned that if MPs voted down her deal, the most likely result would be a paralysis in Parliament and a risk there being no Brexit.

May also said that on Monday she had published the outcome of her latest discussions with the EU about her concerns about the Irish border backstop, one of the biggest stumbling blocks to the deal being widely accepted.

May said the EU repeated they would not renegotiate the withdrawal agreement agreed between Brussels and May's government, and they had also said it was not possible to apply a fixed-end date after which a temporary backstop period would end.

Despite rejecting what are considered two crucial issues, May said she had secured valuable new assurances from Brussels, which have legal force.

She said she fully understood that the new legal and political assurances contained in the letters from EU leaders do not go as far as some MPs would like.

"But I am convinced that MPs now have the clearest assurances that this is the best deal possible and that it is worthy of their support," she said.

In her speech, May added: "We have seen over the last few weeks, there are some in Westminster who would wish to delay or even stop Brexit and who will use every device available to them to do so. I ask them to consider the consequences of their actions on the faith of the British people in our democracy."

May said MPs all have a duty to implement the result of the referendum, warning again of catastrophic harm if they fail.

May sidestepped questions about the consequences of MPs voting against her Brexit deal, insisting it was the only deal on the table.

She said some MPs have changed their views and will now be backing her deal, adding: "No one in Parliament has come up with an alternative Brexit deal that is negotiable and that delivers on the result of the referendum."