Ryanair chief executive Michael O’Leary has joined the chorus of criticism following government suggestions of a high-speed rail link between Heathrow and Gatwick airports.

In his usual caustic tone, O’Leary said: “They have no particular expertise in tunnelling. The last one they did was the Eurotunnel; which went bankrupt even before it opened.”

The department for transport this weekend unveiled proposals for a £5 billion, most underground, rail link following the route of the M25 joining the two airports.

However, the idea has been widely derided, with the Board of Airline Representatives in the UK (BAR UK) yesterday arguing the idea could not be “justified”.

“Building an aviation policy around this concept is misguided and if airlines and airports believed a rail link could work it would have had their support years ago,” BAR UK said.

Willie Walsh, chief executive of International Airlines Group (IAG) – which was created following the merger of British Airways and Iberia – also branded the plans suboptimal.

Now O’Leary has come weighed in with his opinion.

He said: “What you really need to do is build three additional runways: one at Gatwick, one at Stansted and one at Heathrow, which you could actually do for £200 million in each of the three airports.

“Then you would finally have addressed the major problem here in the UK, which is the massive under capacity of airports in the south-east.”

The Ryanair boss also attacked proposals from London mayor Boris Johnson for a six runway airport in the Thames Estuary.

Such a development would leave rivals in Europe “standing” Johnson said recently.

However, O’Leary was unimpressed and said: “Wasting multi-billions building a bloody airport in the middle of the marshes somewhere where you then have got to build motorways to it, rail transport links – it is mad.”