The government has warned that staging the COP 26 climate summit must represent “value for taxpayers’ money”, amid friction with the Scottish government over the policing costs of holding the event in Glasgow.

It emerged on Wednesday that government officials have been scoping out the ExCeL Centre in London’s Docklands for the high-profile international summit, which the UK is due to host in November.

The Scottish first minister, Nicola Sturgeon, responded by accusing Boris Johnson of “playing politics with the biggest issue of our time”, with the build-up to the conference already hampered by the sacking of the former Tory minister Claire O’Neill as its chair.

Asked about the apparent uncertainty over the venue, the prime minister’s press secretary said the government was determined to hold the event in Glasgow as promised, but issued a thinly veiled warning to the Scottish government about allowing the costs to escalate.

“We are committed to holding COP 26 in Glasgow, but the Scottish government needs to work with us to make sure this is a successful summit, which showcases the UK as a world leader in tackling climate change and represents value for the UK taxpayer,” he said.

He added: “It is standard practice to carry out contingency planning for major international events at this scale.”

One Whitehall source with knowledge of the plans complained privately that Edinburgh had not yet provided the government in London with a full breakdown of the costs for staging the event.

Scotland’s chief constable, Iain Livingstone, said earlier this year that he believed the cost of policing COP 26 could run to as much as £200m, and warned it was “fanciful” to suggest it would not have a major impact on people living locally. He added: “Candidly, it is my professional opinion that any suggestion that the climate change conference will not impact on the wider community of Scotland is fanciful.”

The spat appeared to be the latest indication of vexed relations between London and Edinburgh.

A Scottish government spokesperson said: “Scotland looks forward to welcoming the United Nations delegates and participants from around the world later this year. Glasgow is recognised internationally for its strong track record at hosting major international events and we are working collaboratively with the UK government, Glasgow city council, Police Scotland and other partners to ensure the conference is a success.

“The Scottish government has had no notification of any intention to move the venue.” At recent meetings with UK government and United Nations organisers, there has been no discussion of alternative venues.

O‘Neill’s successor is expected to be announced on Thursday, as Johnson reshapes his cabinet. He had approached David Cameron and William Hague about the role, but both turned it down.

Michael Gove has taken oversight of the preparations, as the Cabinet Office is the sponsoring ministry, and gave a speech about it earlier this week – but government sources suggest the job is likely to be considered too onerous to add to his already extensive list of responsibilities.

Other names in the frame include the new peer and Defra minister Zac Goldsmith, whom Johnson put in the Lords after he lost his Richmond Park seat in December.