The Greens have targeted changes to tax as well as more spending for public services.

Co-convener Patrick Harvie said his party was "making a strong case" to use Holyrood's tax powers to protect public spending.

He told the BBC's Politics Scotland programme: "If parties just dug their feet in and said 'my way or the highway' then the whole thing would fall and we would begin to see emergency cuts being made to public services across Scotland.

"I'm not willing to see that happen, but I am entirely willing to put pressure on the Scottish government to give ground on the position that it's taken so far."

The SNP and Greens have struck a deal ahead of the first vote on the Scottish budget, BBC Scotland understands.

With the SNP a minority government, Finance Secretary Derek Mackay has held talks with opposition groups in a bid to win backing for his plans.

It is understood the Scottish Greens have done a deal based on changes to the threshold for the top rate of tax.

The agreement will also also increase the level of spending on local government services.

The details will be announced at Holyrood this afternoon.

Mr Mackay had said he was "confident" of finding "common ground" to get his proposals passed.

Members will debate the draft budget before voting on whether they agree to the general principles set out in the bill.

Previous votes on the budget proposals and on taxation have failed to find any consensus between the parties.

Mike Russell tells the committee that although the UK government has pledged that devolved administrations will not lose any of their current powers during the Brexit process; the attitude has changed "very substantially" on where powers repatriated from the EU should end up.

He says that despite pledges in the referendum campaign that powers repatriated from the EU which fall under devolution arrangements would end up with the Scottish parliament, this attitude has now changed.

SNP MSP Richard Lochhead says this is "very alarming".

Liberal Democrat Tavish Scott asks if the prime minister has explicitly said that immigration is the top priority of the UK government.

Mike Russell says that he is not in any doubt of this point, going on to say that the UK government's two priorities are the judgement of courts outside the UK and migration.

Brian Taylor
BBC Scotland Political Editor

BBC Scotland understands that a deal has been reached to secure the Scottish government's budget. 

The agreement between ministers and the Greens will increase the level of spending on local government services. 

It is also understood that there will be a limited increase in the level of income tax. 

That will be achieved through lowering the planned threshold at which the 40p income tax rate kicks in Scotland. 

The details will be announced at Holyrood this afternoon from 2.30pm.

Join us for extensive coverage of the budget debate.

Lewis Macdonald asks about the different negotiating positions of the Welsh and Scottish governments. 

Mr Russell says that the situation in Wales is "different but complimentary" as they are seeking special status within the UK, but with different details to the Scottish government's position.

Image source, Thinkstock

There is a "spectrum of differences" between Scotland, Wales and Northern Ireland, he says, "but we all come from the same space".

He also tells the committee that "language bedevils the process" - giving the example of the various different and mutually exclusive scenarios that could comprise "membership of single market". 

Brexit Minister Mike Russell says the UK government might want to significantly decrease social protections and employment standards.

Mr Russell says there is an enormous pressure on the UK to keep the regulatory system the same.

He says "the overblown talk of freedom is nonsensical as it will not be that way".

Labour MSP Lewis Macdonald asks about discussions between the Scottish, Welsh and UK governments on the nature of the meetings on Brexit.

Mike Russell says that he and his Welsh counterpart Mark Drakeford have said that changes to the Brexit meetings must be "qualitative not quantitative", saying its about what we discuss and not how many times we meet.

Mike Russell says emphatically that there is currently no agreed UK-wide position on triggering article 50 - "this does not exist at the moment". 

Ian Mitchell from the Scottish government says the lateness of papers and not knowing what is going to be covered has been a problem.

Mr Mitchell says getting a work programme has been been an "uphill struggle" especially with Article 50 coming up soon.

He says they have garnered information from speeches rather than from papers.

Committee convener Joan McAlpine asks about the inter-governmental relationships, saying that the communications from Mr Russell to the committee show that he has received very little notice of the meetings with the UK government which, she says, suggests that the Scottish government has little influence on the agendas of the meetings.

Mr Russell replies that the meetings cannot take place without us but admits it has proved difficult to set accurate dates

"The process hasn't been made easy by the UK government" he says.  

The Joint Ministerial Committee (EU negotiations), chaired by the Secretary of State for Exiting the European Union, is a forum to continue the UK government's work with the devolved administrations in Scotland, Northern Ireland and Wales to secure the best Brexit deal for the whole of the United Kingdom.  

Image source, Scottish government

The Scottish government has published its proposals for Scotland's future relationship with the EU after Brexit.

Prime Minister Theresa May has said she is "willing to listen to options", but Chancellor Philip Hammond has suggested a special deal is "not realistic".

The Scottish government has been studying its options around Brexit, with First Minister Nicola Sturgeon setting up a "standing council" of experts for advice.

The full paper, "Scotland's Place in Europe" can be found here, external.

Mr Russell says the prime minister has promised to give Scotland's Place in Europe consideration and a pledge was given to scrutinise 

The Brexit minister says there is "great disappointment" that the prime minister did not discuss her plans with the JMCEN before her speech.

Mr Russell says Theresa May's hard brexit does not reflect the democratic will.

Brexit Minister Mike Russell makes a short opening statement - beginning by saying the Scottish government's proposals aim to tackle the different democratic outcomes in different parts of the UK in the referendum.

He says the proposals are a compromise and that it is now for the UK government to be flexible and come to the table with a compromise itself.

The plans could benefit the whole of the UK, he says.

Committee convener Joan McAlpine welcomes:

• Brexit Minister Mike Russell
• Ian Mitchell from the Scottish government

Nicola Sturgeon has said "the next few weeks are going to be really critical" in building a UK-wide Brexit position.

The first minister was speaking after meeting Theresa May for talks with other leaders in Wales.

Ms Sturgeon warned time was running out for the prime minister to "square the circle" of different Brexit votes and "heed the voice of Scotland".

Mrs May pledged to engage the devolved governments in the process, but said they "will not agree on everything".