THE boss of Scotland's regional airports said Heathrow is "in desperate need of expansion" after Boris Johnson rubbished calls for a third runway at the hub.

Inglis Lyon, managing director of the taxpayer-owned Highlands and Islands Airports Ltd (HIAL) said he was "deeply disappointed" with remarks by the Foreign Secretary, who said Heathrow expansion was a "fantasy" project that should be consigned to the "dustbin".

In a letter to Scottish Secretary David Mundell, Mr Lyon asked for assurances that Mr Johnson's remarks "do not reflect the views of your Government".

HIAL, which is wholly-owned by Scottish ministers and subsidised by taxpayers, operates and manages 11 small airports in Scotland, including Inverness and Dundee. It also owns the airports in Barra, Benbecula, Campbeltown, Islay, Kirkwall, Stornoway, Sumburgh, Tiree and Wick.

Mr Lyon said the resumption in May of direct flights between Inverness and Heathrow for the first time in nearly 20 years, operated by British Airways, had proved highly popular with passengers.

However, he added that a a shortage of slots at the London hub was "restricting our ability to attract investors and foreign visitors to the Highlands".

Mr Lyon wrote: "Since BA reconnected Inverness to Heathrow in May this year, we have become their top performing domestic route. We need another slot but Heathrow is full and, in our view, clearly in desperate need of expansion.

"We were therefore bitterly disappointed to read that the Foreign Secretary, who is not on the Committee making the decision regarding airport expansion, describing Heathrow's growth as a 'fantasy' project.

"For Inverness, Heathrow expansion is a key part of our future connectivity plans."

Former London mayor, Mr Johnson, a long-time opponent of Heathrow expansion, hit out after reportedly being excluded from the key Cabinet committee that will decide on airport expansion on the south-east.

Ministers will decide between a third runway at Heathrow, extending an existing runway or expanding Gatwick Airport, but the Airports Commission previously advised that a third runway at Heathrow would offer the best economic and connectivity boost for the UK.

Mr Johnson told the Daily Telegraph this was the "wrong choice" and "if it is chosen it simply won't get built".

He added: "We need to consign this Heathrow fantasy to the dustbin."

A number of daily connections between Scotland and Heathrow has halved over the past decade as slots were increasingly allocated to more lucrative long--haul routes.

Heathrow bosses have vowed to increase domestic regional connections if a third runway is granted.