Sri Lanka President Gotabaya Rajapaksa failed in his attempt to flee to Dubai after airport staff stood in his way and is now considering taking a Navy vessel and escaping via the sea route, according to an AFP report from Colombo.

Immigration staff refused to let the president come to the VIP area of the airport to stamp his passport and he would not go through the ordinary queues for fear of being mobbed by the public.

The president and his wife missed four flights that could have taken them to the United Arab Emirates on Monday night and then spent the night at a military base next to the main Bandaranaike International airport.

As president, Rajapaksa enjoys immunity from arrest, and he is believed to want to go abroad before stepping down to avoid the possibility of being detained.

His younger brother Basil Rajapaksa, who served as finance minister and has also been accused of widespread corruption, was also prevented from boarding a flight to the US, via Dubai, on Tuesday morning after other passengers protested.

Airport staff refused to let him use the fast-track concierge service and stopped him getting on the flight. According to airport officials, as the situation grew tense, Basil Rajapaksa, who has dual US citizenship, retreated.

A top defence source said the president's closest military aides were discussing the possibility of taking him and his entourage overseas aboard a naval patrol craft, AFP reported.

"The best option now is to take the sea exit. He could go to the Maldives or India and get a flight to Dubai," the defence official said.

He said that another alternative would be to charter a plane to fly him from the country's second international airport at Mattala which is sparingly used.

After news of the Rajapaksa family’s attempts to flee emerged on Tuesday, a motion was filed to the supreme court seeking an order to prohibit Basil Rajapaksa, his older brother Mahinda Rajapaksa, who was forced to resign as prime minister in May, the prime minister, Ranil Wickremesinghe, and several others who served in president Gotabaya’s Rajapaksa’s regime from being allowed to leave the country.

Sri Lanka's president was considering using a navy patrol craft to flee the island on Tuesday following a humiliating standoff with airport immigration, official sources of AFP said.

Gotabaya Rajapaksa has promised to resign on Wednesday and clear the way for a "peaceful transition of power" following widespread protests against him over the country's worst economic crisis.

The 73-year-old leader fled his official residence in Colombo just before tens of thousands of protesters overran it on Saturday. He then wanted to travel to Dubai, officials said.

Hasty retreat

Basil had to obtain a new US passport after leaving his behind at the presidential palace when the Rajapaksas beat a hasty retreat to avoid mobs on Saturday, a diplomatic source said.

Official sources said a suitcase full of documents had also been left behind at the stately mansion along with 17.85 million rupees in cash, now in the custody of a Colombo court.

There was no official word from the president's office about his whereabouts, but he remained commander-in-chief of the armed forces with military resources at his disposal.

Rajapaksa is accused of mismanaging the economy to a point where the country has run out of foreign exchange to finance even the most essential imports, leading to severe hardships for the 22 million population.

If he steps down as promised, Prime Minister Ranil Wickremesinghe will automatically become acting president until parliament elects an MP to serve out the presidential term, which ends in November 2024.

Sri Lanka defaulted on its $51-billion foreign debt in April and is in talks with the IMF for a possible bailout.

The island has nearly exhausted its already scarce supplies of petrol. The government has ordered the closure of non-essential offices and schools to reduce commuting and save fuel.