THE SNP's Westminster leader has slammed the UK Government over its new Brexit deal, saying his party could "never vote" for it.

Ian Blackford argued that the deal - which has set out special arrangements with Northern Ireland in order to avoid a hard border on the island of Ireland - leaves Scotland as the only UK nation with "no say" on its relationship with the EU. 

Both England and Wales voted to leave the EU back in 2016, but Scotland and Northern Ireland voted Remain. 

READ MORE: Brexit deal reached - but DUP say they won't back it

Boris Johnson's latest deal would see the Northern Irish Assembly given the chance to vote on whether or not to continue its special arrangements with the EU every four years. 

Earlier the First Minister also slammed the deal for similar reasons, adding Scotland had been left with "no respect" for how it voted. 

On Twitter, Blackford wrote that Scotland had been treated "abhorrently" over Brexit.

He said: "This deal would leave Scotland as only part of UK being taken out of EU, along with the SM and CU without consent and with no say on the future relationship. @theSNP could never vote for that. Scotland really has been treated abhorrently throughout this process. #indyref2020"

Earlier, the SNP's Constitutional Relations Secretary Mike Russell hit out at Michael Gove over comments he made on the Northern Irish side of the agreement.

READ MORE: Mike Russell slams Gove over 'untenable' position on indyref2

Calling it a great deal, Gove said the "future of Northern Ireland is now decided by the people of Northern Ireland".

The Tory Cabinet member has previously outright rejected the idea of Scotland having a second independence referendum to determine its own future in the wake of the Brexit result. 

While running for the Tory leadership position earlier this year, Gove said he would respond to a request for a Section 30 order with a "flat no". 

Russell said that position was now "untenable" in the wake of the new deal. 

It is currently unclear whether or not the new deal will pass through the House of Commons on Saturday.