LONDON, June 21 (Xinhua) -- The first crucial bill in Britain's journey to leaving the European Union was Thursday on its way to the Buckingham Palace for Royal Assent by Queen Elizabeth.

The European Union Withdrawal Bill endured a stormy passage as it made its ping-pong journey between MPs in the House of Commons and peers in the unelected House of Lords.

Pro-EU members of the House of Lords attempted to change the bill by agreeing a series of amendments that would have been damaging for Prime Minister Theresa May. But late Wednesday night they gave a final nod, leaving it intact.

A spokesman at 10 Downing Street told Xinhua Queen Elizabeth is expected to sign the bill early next week after which it will go on the statute books as British law.

The bill will enshrine in British law all EU law passed during Britain's 45 year membership if the bloc.

May welcomed the passing of the Brexit bill through the Houses of Parliament as a crucial step in delivering a smooth and orderly Brexit.

May said the votes in both Houses of Parliament show people in Britain, and to the EU, that the elected representatives are getting on with the job, and delivering on the will of the British people.

"Over the next few weeks we will publish more details of our proposed future relationship with the EU in a White Paper, and will bring the Trade and Customs Bills back to the House of Commons," said May.

The final hurdle in the bill came when MPs voted by 319 to 303 on a sticking point clause after rebel Conservative were given assurances they would have a meaningful say on a final deal London brokers with Brussels on Britain's future relationship with the EU.

In a day of high drama at Westminster party managers pulled out all the stops to ensure MPs were present to vote.

Labour MP Naz Shah, was taken to the House of Commons from her sick bed, transported in a wheelchair while carrying a 'sick bag' fearing she may vomit.

Mom-to-be Jo Swinson, deputy leader of the Liberal Democrats, arrived to vote while another heavily pregnant MP, Labor's Laura Pidcock, also despite came in to place her vote.

MPs in the debate revealed the extent of the behind-the-scenes high drama surrounding the Brexit bill's journey.

Former attorney general Dominic Grieve, who had put forward a controversial amendment, told how some MPs had faced vilification and abuse, including death threats

"There is enough madness around at the moment to make one start to question whether collective sanity in this country has disappeared," said Grieve.

Anna Soubry, one of six Conservative rebels who voted against the government on Wednesday told how she feared the editor of one of Britain's leading pro-Brexit newspapers had "made a small doll that looks like me and is sticking pins in its throat, as every time I want to speak".

The Daily Mail claimed calls have been made in some local Conservative party constituencies to fire MPs who voted against May in the crucial Brexit debate by de-selecting them as party candidates.