Liz Truss is disputing a bill she has been asked to pay relating to a country house which she had use of as foreign secretary.
The bill is reportedly for £12,000 but the former prime minister’s spokesman claims the actual figure is lower.
The invoice, first reported in The Mail on Sunday, covers the period in August 2022 when she used Chevening House in Kent, during the time she was running to be Conservative leader before being elected to No 10 the following month.
Ms Truss claims most of the invoice relates to using the grace-and-favour home for government business and she maintains she should not be liable for the majority of it.
The official business included meetings with cabinet secretary Simon Case when they were planning a transition to a Truss government.
If she did pay, there would have been a breach of civil service protocol because civil servants are not allowed to accept hospitality from a political candidate, her team argues.
Ms Truss has asked for this part to be billed separately.
She will pay for personal costs relating to guests. The bill reportedly includes missing items including bathrobes, which she is happy to replace.
A spokesman for Ms Truss said: “Liz always paid for the costs of her personal guests at Chevening.
“The latest invoice contains a mixture of costs for her personally and costs for official government business with civil servants including Simon Case and senior officials from other departments who met at Chevening during the transition preparations.
“The latter constitutes the majority of the bill. It would be inappropriate for her to pay the costs for officials as it would have breached the civil service code for civil servants to accept hospitality during the leadership campaign.
“She has therefore asked for this to be billed separately.”
Chevening House, which has 115 rooms and is Grade 1 listed, was left to the nation by the 7th Earl Stanhope after he died in 1967.
Since then, the prime minister of the day has decided who uses it, with that person usually being the foreign secretary.
Ms Truss was the shortest-serving prime minister in UK history, resigning last October, just 44 days after taking over from Boris Johnson.
It came after her tax-cutting mini-budget spooked financial markets.
She has said she was never given a “realistic chance” to implement her radical tax-cutting agenda and blamed what she called a “powerful economic establishment” for removing her from Downing Street.