Heathrow will be obliged to raise the number of domestic flight connections as a condition of building a third runway.

Transport secretary Chris Grayling said that establishing new air links across the UK would form a cornerstone of the government’s pending decision on runway capacity around London.

The move would ensure that the benefits of airport expansion spread beyond the south-east and to parts of the UK that had suffered from cuts in long-haul routes such as Newcastle, The Times reported him as saying.

This comes despite claims from Willie Walsh, head of British Airways’ parent company International Airlines Group, that domestic flights would be squeezed out of an expanded Heathrow. He said airport charges would have to be raised to pay for the runway, making them unviable.

However, regional airlne Flybe has been pressing for access to Heathrow to open domestic routes should the airport win the green light to expand over rival Gatwick.

A decision on a new runway – which could be built as an expansion of either Heathrow or Gatwick – will not be made this week to allow the issue to be debated in a cabinet meeting, it emerged yesterday.

Grayling is now expected to make an announcement on the issue in the House of Commons next Wednesday (October 26).