NICOLA Sturgeon is optimistic she can secure a “Valentine’s Day deal” with David Cameron on the transfer of more tax powers to Scotland.

After a 45-minute meeting in Downing Street, the First Minister emerged to announce that, after months of wrangling, there was now clear impetus towards a mid-February deadline to get the so-called fiscal framework agreed ahead of the May election campaign.

“We’re looking for a Valentine’s Day deal,” declared Ms Sturgeon.

“With a fair will and good faith on both sides we can do that. But we need to get to the point there’s a proposal on the table that is fair and equitable. The PM and his colleagues will want to think it’s fair and equitable from their side as well.

“I’m optimistic and certainly the PM and I have agreed that’s what we are trying to do. So there’s no sense on either side we don’t want to reach agreement; I’m hopeful we’ll get there.”

With the Scottish Government’s Budget for 2016/17 published tomorrow, she explained that as the SNP leader she wanted to go into the May election with the powers in the Scotland Bill on their way to being implemented.

“It’s no secret I think they are inadequate powers but I want to be in a position of having a manifesto that sets out how we are going to use those powers. That’s why the fiscal framework is so important but it has to be the right fiscal framework. I’m not signing up to something that is unfair to Scotland.”

Failure to get a deal would lead to the bill not being ratified by the Scottish Parliament and a constitutional crisis as the Holyrood campaign unfolded.

The framework is crucial to the implementation of the new tax powers. But the original mechanism proposed by the UK Government was rejected by Ms Sturgeon and her colleagues.

They, and others, feared that in reducing Scotland’s £30 billion annual grant as the new powers were introduced would have resulted in Holyrood losing hundreds of millions of pounds a year.

Ms Sturgeon said: “The proposal that was on the table would have resulted in systemic reductions to the Scottish Budget year after year regardless of the decisions the Scottish Government took. As First Minister I’m not going to sign up to something that would be so disadvantageous to Scotland and to the Scottish people.

“I hope we can agreement on a deal that is fair; that’s all we are looking for is fairness, nothing more, nothing less.”

For the UK Government, Lord Dunlop insisted both administrations were acting in “good faith”.

“We’re both committed to getting a deal that’s good for Scotland, good for the UK as a whole and built to last,” said the Scotland Office Minister.

“We’re both determined to get a deal in place so that when people go to the polls in May they know what the powers of the Scottish Parliament are and the debate can be about how those powers are used.”

During the No 10 talks, Mr Sturgeon also raised her concerns about the implementation of the Conservative Government’s controversial Trade Union Bill, which would introduce a threshold for strike ballots and new measures on picketing.

Mr Cameron believes the legislation strikes the right balance between the rights of trade unionists and the general public but critics, including the FM, claim it is an unwarranted attack on union freedoms.

Ms Sturgeon said there had been a “robust exchange of views” but she gave little evidence her government could do anything to stop its measures being introduced in Scotland given they are reserved powers.

Lord Dunlop said while the UK Government was willing to talk, it would not budge on the principle of the legislation.

Also on the agenda was co-operation on countering terrorism, where there was much more consensus and an agreement to strengthen co-operation on intelligence and security matters.

Under the changes agreed, the Joint Terrorism Analysis Centre in London will increase the number of reports it shares with the Holyrood Government and the First Minister will receive security briefings on a more frequent basis.

Lord Dunlop said: “The UK Government is absolutely committed to working together with the governments of our devolved nations on security and counter-terrorism matters, and today’s discussions reflected that. Put simply, every citizen in every part of the United Kingdom must have the same level of safety and security.”

Elsewhere, Ms Sturgeon opened the day’s business on the London Stock Exchange in the City of London, had meetings with some 80 Scottish business leaders and later dined with investors.