British Airways is offering free flights for kids this summer

The offer is valid for under-12s on six routes

In an unprecedented move, British Airways is offering free child places on six routes to and from Heathrow.

The promotion, which applies for flights from 1 June to 31 October, is primarily intended to fill planes on links where business travel dwindles in summer.

The UK destinations are Belfast City, Edinburgh, Inverness, Leeds/Bradford and Newcastle. Aberdeen, Glasgow and Manchester are notable absentees from the list.

In addition, Billund airport — adjacent to the original Danish Legoland — is included.

Up to two children can fly for free with each fare-paying adult. BA automatically seats children with adults at no charge.

A test booking made by The Independent found a hand-baggage only fare for an adult and two children from Heathrow to Billund on 15 August, returning a week later, for a total of £93 return — just £31 each, a historically low fare.

The corresponding fare on Ryanair from Stansted on those dates is £183, almost twice as much.

Adam Daniels, British Airways’ chief commercial officer, said: “Saving every penny counts when it comes to family holidays so flying kids for free will make it cheaper to fly away for fun and see more of the UK and Europe this summer.”

“The offer also looks set to give UK tourism a boost by encouraging families to visit London, the North, Scotland and Northern Ireland for their holidays.” The offer applies to one-way and return tickets, so families could fly from Heathrow to Inverness then travel overland to Edinburgh or Newcastle.

Under-16s do not pay Air Passenger Duty, which adds £13 to flights departing from UK airports.

If, as expected, the promotion proves popular, availability will soon be an issue. “Blackout periods” apply on some destinations.