John Healey has said there is a pro-growth case for going ahead with a third runway at Heathrow despite the prime minister declining to back it.

Healey’s predecessor as chancellor, Rachel Reeves, put approval of the long-planned runway at the heart of her “growth speech” last year, saying it would “make Britain the world’s best-connected place to do business”.

However, since arriving in No 10 in July, Andy Burnham has ducked the issue of whether the runway should go ahead, suggesting it should be “a matter for London and Londoners”.

A recent Sunday Times report suggested the prime minister had told the transport secretary, Heidi Alexander, that he was “unconvinced” by arguments for the megaproject.

Asked for his views in Bangkok this week, Healey said the government would study responses to a public consultation, which recently closed. He appeared to strike a markedly more positive note than Burnham, however.

“I think in recent decades, and this is true in Heathrow and airports right across the UK, that they have been a big part of jobs and growth. And the case for a third runway at Heathrow has always been a case for growth,” he said.

Healey has insisted economic growth is his and Burnham’s “number one mission” in government.

Heathrow’s chief executive, Thomas Woldbye, has warned that investors could reassess their backing for the £33bn infrastructure project if it does not receive the prime minister’s support.

“Our shareholders would like to do this,” he said earlier this week. “They do think that things are taking a long time, and so far they have decided to be OK with that … But of course we cannot wait for ever.”