'Theresa May is facing a fresh Brexit wrangle as the Scottish parliament is expected to formally refuse its consent to key legislation after months of rows over its impact on devolved powers.
MSPs will set themselves at odds with Westminster by backing a Scottish government motion that makes clear that Holyrood "does not consent to the EU Withdrawal Bill".
The move could trigger a constitutional crisis, as it would be the first time the UK government has pushed through laws against the will of Scotland, if Ms May decides to press ahead with the legislation.
It comes as the prime minister struggled to break the deadlock over customs arrangements after Brexit, which have divided her cabinet.
Scottish Labour, the Greens and the Liberal Democrats have said they will back the SNP in the Holyrood vote later today, which would give Nicola Sturgeon's party the numbers to defeat the Scottish Conservatives on the motion.
Scottish government Brexit minister Mike Russell said the bill "rides roughshod over devolution", as it could see some powers returned to Whitehall, rather than Holyrood, after the UK leaves the EU.
"Devolution is the settled constitutional will not just of the Scottish people, of the whole of the UK," he told the BBC's Today programme.
"Westminster is trying to subvert that and to change that by the back door."
Such a move would not prevent the UK government from introducing the legislation - but it would be the first time Westminster has pushed through laws against the wishes of the Scottish Parliament.
Tory MSP Adam Tomkins said: "The Scottish Conservatives will vote to give our consent to the amended Withdrawal Bill today.'
Read more: Brexit: EU Withdrawal Bill set to be rejected by Scottish Parliament, in fresh blow for Theresa May
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