In a clear push for liberalisation, Transport Minister Raymond Lim warned that the 10-member group's "standing and credibility as a regional integrated entity" was at stake if they failed to do so.

Speaking at the opening of the 24th Asean Senior Transport Officials Meeting at Raffles City Convention Centre on Monday, Mr Lim, who is also Second Minister for Foreign Affairs, said: "It is vital that all remaining obstacles are cleared in order to make it a reality, so as not to affect Asean's credibility to deliver on its plans. We are so close to the finish line."

Liberalisation will significantly boost intra-Asean tourism.

Last year, more than 27 million people travelled within the region, a 20 per cent jump over 2005, he noted.

Opening up the capital cities would allow Singapore Airlines, for example, to fly as often and carry as many people as possible from Singapore to Kuala Lumpur, or Jakarta, Bangkok and Manila.

Competition is also expected to bring fares down, especially on more tightly regulated routes like Singapore-KL.

SIA and Malaysia Airlines now dominate that sector, operating about 85 per cent of the more than 200 flights a week and charging about $400 for a return flight that lasts 45 minutes each way.

But things could soon change: Just last week, Malaysia said it has decided to open the lucrative route to budget carriers.

Singapore and Malaysia officials are expected to discuss the details on the sidelines of the Asean forum, which ends on Wednesday.

Apart from air issues, Asean officials will also talk about land and sea transport. Among other things, they will work out plans for an integrated and more competitive maritime industry in the region.

Asean, with its abundant natural resources and labour, can be attractive to foreign investors, Mr Lim said, but it has to "compete hard" with giants China and India.

For this reason, the group "must redouble its efforts to integrate, with transport being a key propellant of growth", he said.

Over the next two days, transport officials will also meet dialogue partners China and India.

Issues deliberated at the three-day meeting will be tabled at the 13th Asean Transport Ministers Meeting, which opens on Thursday.