Image copyright Scottish Parliament Image caption Mr Mackay said he was "positive" about getting his budget plans through parliament

Scottish Finance Secretary Derek Mackay says he is "positive" about winning support for his budget from opposition MSPs.

With the SNP a minority government, Mr Mackay needs support for his plans from at least one opposition party.

He said talks with the Lib Dems and the Greens had shown there was "room for manoeuvre" to strike a deal.

Both of those parties have warned that the government will have to make concessions to win them over.

Detailed discussions have been ongoing since Mr Mackay outlined his budget proposals in December.

With a deal with the Conservatives or Labour unlikely, the Lib Dems and Greens have emerged as the favourites to reach an agreement, and the finance secretary said there were "constructive" and "positive" talks ongoing.

Scottish Greens co-convener Patrick Harvie told BBC Radio Scotland on Thursday that the SNP needs to "give some ground" and "move some way towards some other party" if it is to win backing for the budget.

He highlighted "astonishing cuts to local government services", and has also been critical of Mr Mackay's "standstill income tax policy".

And after the pair clashed over tax during a meeting of the finance committee on Wednesday, Mr Harvie said it would be "a huge missed opportunity" if the government were to "dig in their heels and insist on a no-change tax policy now that they have the power, and the political support, for real change".

Image caption Willie Rennie and Patrick Harvie have been holding detailed talks with Mr Mackay

Meanwhile Mr Rennie underlined during first minister's questions that "the Scottish government has no majority for its budget".

He highlighted a £90m cut to college funding, while claiming that the government's plans for a schools attainment fund were "£70m short of what is required".

Nicola Sturgeon responded: "We will continue to discuss with Willie Rennie and others their suggestions for amendments to the draft budget."

'Room for manoeuvre'

Mr Mackay told BBC Scotland that he was "engaging constructively and positively with other parties".

He said he would "not necessarily" find common ground with the Conservatives or Labour, but noted that "particular discussions with the Liberal Democrats and the Greens are showing there is room for manoeuvre".

He said: "I'm positive about getting a budget through the Scottish Parliament.

"I've made it clear the government wants to deliver our tax position as was set out in the manifesto, that commanded the support of the people.

"But the budget isn't settled until the very end of the process, so I'll continue to engage on all matters in relation to the budget."

Image caption There will be a series of budget votes in the Holyrood chamber in February

Asked about how the positions of opposition parties, Mr Mackay said: "The Lib Dems have set out a position around education and mental health, and those are the kind of areas you would expect me to discuss with them to ensure we can reach a position they can support.

"The Greens are looking for a number of things, and they've made their public position clear around taxation. But they also recognise that the government has a mandate and a manifesto which we want to fulfil, and they're looking for a different position."

Mr Mackay noted that the government "want to adhere as close to the manifesto as possible" on tax, but added: "None of these matters are absolutely closed."

He will give evidence to the finance committee on his spending plans on Monday, after which the committee will consider its report on the draft budget.

A series of votes will then follow through February, with a separate vote on the tax proposals prior to the final budget vote at the end of the month.

Analysis by BBC Scotland political reporter Philip Sim

The Lib Dems have pulled into pole position to be the party which strikes a budget deal with Derek Mackay.

Patrick Harvie, with one eye on the tax vote which will precede the final budget vote, has set his stall out very firmly on that front. When launching the Green manifesto last year, he outlined "progressive taxation" as the number one policy he would look to have implemented.

But Mr Mackay doesn't want to compromise on tax. He sees his position as well-balanced, and moreover endorsed by the public in last May's election.

It's possible there may also be an element of distrust in the Greens - SNP members are unlikely to have forgotten that they scuppered the 2009 budget after a last-minute change of heart.

Tax is also a big issue for Willie Rennie - but it is not necessarily top of his shopping list.

During first minister's questions, he more or less named his price - cash for education, with some funding for mental health thrown in, could win those crucial Lib Dem votes (or, at the very least, abstentions).

The looming council elections have a role to play too, with neither party wanting to look like they are giving in too easily to the government, particularly in terms of funding for local services,

There's a long way to go in the talks yet - but a deal is looking more and more likely.