PHILIP Hammond has been accused by Alex Salmond of “politicising” the Foreign Office after the Whitehall department refused to brief the former First Minister at dinner in the British embassy during a trip to Iran.

The Foreign Secretary dispatched a memo to the SNP's foreign affairs spokesman making clear the delegation, which also included SNP MP Tasmina Ahmed-Sheikh and SNP MSP Bill Kidd, was not entitled to hospitality on the UK taxpayer.

The MP resorted to hosting dinner in his Tehran hotel during December's trip for himself, the delegation and embassy staff too at a cost of just over £80.

The ex-party leader’s trip, aimed at bolstering economic and cultural links between Scotland and Iran, was controversial with his political opponents, who accused him of grandstanding and trying to “hollow out” Mr Hammond’s role.

But Mr Salmond appeared aggrieved, particularly as the treatment meted out to him and the Scottish delegation contrasted sharply with that offered ex-premier Tony Blair, who has been hosted at British embassies in Paris and Washington.

“It’s a quite serious matter,” the ex-FM told The Guardian, “because it indicates the deep politicisation of the Foreign Office under Hammond and his Tory special advisers.

“The Foreign Office permanent under-secretary should be putting his foot down to make it clear it is the British Foreign Office, not the Tory Foreign Office.”

Mr Salmond added that it was worth noting that, while Foreign Office staff were being prohibited from offering “elementary courtesy” to a parliamentary delegation from the Westminster and Holyrood parliaments, including privy councillors and members of the Council of Europe, they had been “for years offering bed and board for Tony Blair”.

A Foreign Office spokeswoman said: “Overseas posts follow clear guidance on arrangements for visiting parties. Visiting politicians from a single party are offered a general political briefing but it is not the role of overseas posts to provide hospitality or to arrange meetings unless it is for an official visit on her majesty’s government business. All embassy expenditure is kept under close scrutiny to ensure the best value for money for the taxpayer.”

A second SNP-arranged delegation, focusing on education and business, is due to travel to Iran in the spring.