NICOLA Sturgeon’s pro-independence partners at Holyrood have demanded a firm timetable on a second independence referendum, adding to the pressure on the First Minister to name a date.

Patrick Harvie, co-convener of the Scottish Greens, said people in the Yes movement were “impatient” and the SNP government should set out its position “very soon”.

Unionist campaigners claimed the Yes movement was starting to “splinter” at the top.

The First Minister promised last year that she would set out a “precise timescale” on a new vote this autumn, once the terms of Brexit became clear.

READ MORE: Sturgeon under pressure to outline plans for second independence referendum

But she admitted last week that she may not be able to overcome the UK’s government rigid refusal to grant Holyrood the power needed for a second referendum.

She said if that happened, she would make it an issue at the 2021 Holyrood election and seek a fresh mandate, rather than attempt to hold a wildcat Catalan-style referendum.

Her comments dismayed many in the Yes movement who want a referendum sooner.

Polls suggest Unionist parties are on track to have a majority at Holyrood after 2021, scuppering any chance of a referendum.

At last month’s SNP conference, MP Angus MacNeil said his party mustn’t “dither” like the Jacobites and turn back on the road to victory, as “the opportunity is here and now”.

Speaking to the Herald to mark 10 years as the Greens’ leader at Holyrood, Mr Harvie said he wanted action in the current parliament.

He said: “I don’t know if it will happen within this term. I don’t think anyone would honestly answer that question by saying ‘Absolutely, yes’ or ‘Absolutely, no.’

“I hope that we don’t have to wait too long. I think there’s a great many other supporters of independence, of whichever political party they support, who are starting to get impatient.

“If not impatient for a starting gun to be fired, at least impatient for some kind of timeframe.

“We know now what is in the [Brexit] withdrawal agreement.

“I think very soon now we need to have a sense of what the Scottish Government sees as the next steps forward.”

He said it was unacceptable that Theresa May’s Brexit plan did not give Scotland a voice in Europe, despite Scots voting 62% to Remain.

READ MORE: Sturgeon admits Indyref2 may be after 2021

He added: “It would good to see that decision [on a referendum] made during this parliament when we know that there’s a clear majority for the principle that it should be for the people of Scotland to make that decision.”

Pamela Nash, chief executive of the anti-independence group Scotland in Union, said: "These comments reveal that the campaign to leave the UK is starting to splinter, creating yet more headaches for Nicola Sturgeon.

"Unfortunately for Patrick Harvie, polls show that the majority of people in Scotland want to remain in the UK, even if we leave the EU with no deal."

Scottish LibDem MSP Alex Cole-Hamilton said: “The Green Party manifesto said they wanted 1m signatures on a petition before reopening the independence question. “Perhaps Patrick Harvie could tell us how many signatures he has got before he starts pushing for another unwanted referendum?”

An SNP spokesperson said: “SNP members are out campaigning for independence, making the positive case for taking Scotland’s future into our own hands - and we welcome the Scottish Greens’ enthusiasm for joining us in making that case.

“Never has it been more obvious that Scotland needs hope for the future with independence to escape the chaos and damage of Brexit.”