Preparations for this year’s climate summit in Glasgow are being overshadowed by a bitter row between the UK and Scottish governments over a key building near the venue.

UK government sources have accused Scottish ministers of refusing to hand over a building the Scottish government wants to use as its base for the COP 26 climate talks in November.

Scottish ministers say they booked the Glasgow science centre, a publicly funded venue on the opposite bank of the Clyde from the main conference site, only after the UK government said it would be outside the summit security zone last November.

The dispute deepened after Claire O’Neill, the former minister who was sacked as the summit’s chair by Boris Johnson last week, alleged the two governments “were in an extraordinary state of standoff” over the event.

O’Neill told BBC Radio 4’s Today programme that she had been told the Scottish government had “behaved disgracefully” by booking buildings on the summit site – a claim rejected by Scottish government officials and independent sources.

In a letter to the prime minister published by the FT, O’Neill said that Johnson was even considering moving the event to an English city because of “ballooning costs”. That claim was rejected by a Whitehall source who said there was “zero chance” of it being relocated.

O’Neill told Today that the “playground politics, the yah boo of this, has to stop”. She suggested to Johnson that Nicola Sturgeon, the first minister of Scotland, be given a key role at the summit which “the prime minister heartily and saltily rebutted.”

Spurred on by O’Neill’s disclosure, Sturgeon wrote to Johnson on Tuesday afternoon asking him to allow Scotland’s environment and climate secretary, Roseanna Cunningham, to take part in climate change ministerial meetings that he has promised to chair in London.

Johnson is very likely to reject that request. At the Conservative’s conference in October, he told a raucous Scottish Tory fringe event that he did not want Sturgeon “anywhere near” the climate summit.

The spat deepened after a Whitehall source said that the Scottish government had failed to reply to a formal request from Michael Gove in mid-January to relinquish use of the centre and hand it to the climate summit secretariat.

A spokesman for Sturgeon insisted her government was willing to discuss how the centre could be used. Ministers in Edinburgh were open to the idea of sharing it, he said, but refused to confirm that they would vacate the building entirely.

“It’s a mischaracterisation of our position to suggest we’ve been behaving in anything other than a responsible or cooperative way over the organisation of COP 26. That’s the entire basis on which we are taking things forward. It really shouldn’t be a party-political spat,” he said.

Other sources said that the Foreign Office had considered using the science centre last year but failed to book it in time. The event is expected to be the largest gathering of foreign leaders, diplomats and dignitaries ever hosted by the UK, dwarfing previous global summits. Up to 30,000 people are expected to attend, including 200 world leaders.

Police Scotland’s chief constable said last month that the force estimated policing the event could cost more than £200m, increasing tensions between the two administrations.

The Scottish government said on Tuesday the UK government should foot the entire bill – a position rejected by the UK government. The Whitehall source said there were well-understood processes for setting and sharing costs in situations like this.

The UK government believed last year the main Scottish Events Campus (SEC), which includes the SEC Hydro venue, the Scottish exhibition centre, the Armadillo theatre and the Crown Plaza hotel, would be enough.

They now argue the summit should expand across the Clyde to include the science centre, which sits opposite BBC Scotland’s headquarters at Pacific Quay.

Environment and climate justice campaigners also approached the science centre to use it as a base for their alternative summit but were told the Scottish government, which is the centre’s largest funder, had already taken it.