The British parliament has passed all stages of the Withdrawal Agreement Bill, the legislation that incorporates the EU-UK Brexit deal into British law.

The bill will become an act when it is signed into law by Britain's head of state, Queen Elizabeth. This is expected as early as tomorrow.

Earlier today, the House of Commons rejected all five amendments to to the Withdrawal Bill proposed by the House of Lords. The government won all five votes with very large majorities.

UK Prime Minister Boris Johnson is expected to sign the instrument of ratification of the Withdrawal Agreement in the coming days.

The President of the European Council, Charles Michel, and the President of the European Commission, Ursula von der Leyen, will sign the instrument of ratification of the Withdrawal Agreement on Friday morning.

They will then visit Albania and North Macedonia, two countries that are seeking to join the EU.

The European Parliament's constitutional affairs committee begins its consideration of the Withdrawal Agreement tomorrow afternoon, with a final vote on the agreement expected on Wednesday, 29 January in Brussels.

The UK will cease to be a member state of the EU on Friday, 31 January at midnight Brussels time, or 11pm London time.

Earlier, there were claims the UK is facing a constitutional crisis after each of the three devolved administrations voted against Brexit legislation, the Scottish National Party's Westminster leader has said.

Ian Blackford spoke after the Welsh Assembly voted yesterday to reject the European Union (Withdrawal Agreement) Bill - following in the footsteps of the Scottish Parliament and the Northern Ireland Assembly.

Mr Blackford accused the UK government of using the legislation for a power grab on the parliaments in Edinburgh, Cardiff and Belfast, criticising the "gross disrespect from Boris Johnson and his Brexit fanboys that are in Number 10 Downing Street".

After the vote in Cardiff, Scottish First Minister Nicola Sturgeon tweeted: "All three devolved parliaments have now rejected the EU Withdrawal Bill - it is unprecedented and momentous.

"For the UK to ignore that reality will simply demonstrate how broken the Westminster system is."

Welsh First Minister Mark Drakeford said the bill was "flawed and doesn't protect the interests of those we serve".

Meanwhile, Mr Blackford said the Scottish Parliament would lose 28 devolved powers covering areas such as farming, fishing and the environment.

He raised fears this could be just the first such attack on devolution from Westminster.

"The Prime Minister has got to change his position, he's got to respect the first ministers in all the devolved administrations."

The Sewel Convention, a key feature of the UK's political arrangements, sets out that the UK parliament will "not normally" legislate on devolved policy areas without the consent of the administrations.

Mr Blackford, speaking on BBC Radio Scotland's Good Morning Scotland programme, said: "If you can argue, as the government seems to have done in this case, that the situation is not normal, then you can always say the situation is not normal.

"What is to stop you turning around and taking powers back from the Scottish Parliament at another time?"

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The actions of the devolved institutions did not stop the Withdrawal Bill from passing through Westminster.

Mr Blackford added: "There's 28 devolved powers that we're going to be losing as a consequence of this. But really it is about this issue of respect.

"What we've got here is the government acting with a big stick, that is effectively telling not just Holyrood but Cardiff and Belfast as well 'this is what going to happen and you don't have a say in this'.

"We're supposed to have a family of nations and Scotland's place in the United Kingdom is supposed to be respected.

"None of that is happening and I think that is why you have got legitimate concerns."

He added: "The Queen is going to be asked to give Royal Assent to this Act and it is an Act that doesn't have the support of three of the four Parliaments in the United Kingdom.

"That is unprecedented and I would suggest it is in effect a constitutional crisis.

"The Prime Minister has got to change his position, he's got to respect the first ministers in all the devolved administrations."

Additional reporting: PA