Theresa May is facing pressure to abandon her Brexit deal and quit as British prime minister within days, according to people familiar with the matter.

Several senior government officials said they were shocked that the premier's new offer intended to win votes in Parliament for her European Union divorce agreement had been so badly received so quickly.

Speaking on condition of anonymity, the individuals said May's allies know there is little hope of her Withdrawal Agreement Bill passing a crucial vote in the House of Commons, even after she promised MPs the chance to call a second referendum on Brexit.