BA stopped flights between the two airports in 1997.
A Highland MSP has called on British Airways to restore flights between Inverness and Heathrow following the go-ahead to build a third runway.
Labour's David Stewart said BA's chief executive gave him a public assurance last year that the service would be reinstated if the runway went ahead.
BA flights to the London airport were stopped in 1997.
Mr Stewart said he would be writing to Willie Walsh urging him to keep his promise.
He added: "Heathrow is the biggest airport in Britain. It's very important for tourism and very important for connections with Europe and the rest of the world. I want to see this service back."
The UK government gave the go-ahead on Thursday for Heathrow to get a third runway, and a sixth terminal.
The employers organisation, CBI Scotland, said a new runway would increase the prospect of British Airways restoring the Inverness to Heathrow link.
Its director, Iain MacMillan, said: "It's very important and we'll remind British Airways of that as we move forward."