The government today released four letters between ex-premier Mahathir Mohamad and two Singapore leaders in a bid to counter criticism from Mahathir over an aborted bridge project.

The letters, written in 2002, reveal details of bilateral negotiations on issues such as the building of a new bridge to join the countries, a project that Mahathir long-championed.

Prime Minister Abdullah Ahmad Badawi abruptly dropped plans for the bridge in April, citing legal difficulties and public opposition to concessions sought by Singapore, sparking strong criticism from Mahathir.

The letters dealing with the bridge support the government's argument that Singapore's approval of the deal was conditional on concessions. Those sections of the correspondence appear to have been highlighted in white and with pen.

One letter is from Mahathir to Singapore's Senior Minister Lee Kuan Yew, while another is to the city-state's then-premier Goh Chok Tong. The other two are from Goh to Mahathir.

Malaysia cancelled the bridge after nearly a decade of negotiations, citing public opposition to Singaporean requests for the use of Malaysian airspace and for sand for reclamation projects.

Mahathir criticised Abdullah for the decision and accused the government of compromising Malaysia's sovereignty by broaching the sand and airspace issues.

Letter posted on website

The letters have been posted on the website of state news agency Bernama in an apparent attempt to win over public opinion in the increasingly bitter dispute between Mahathir and the government.

The move follows a statement from the government on Friday that it had declassified documents to "put the record straight on a string of allegations raised by the former prime minister".

The statement contained excerpts of the letters and accounts of talks with Singapore which also support the government's decision to scrap the bridge.

The release of the letters are the latest installment in the dispute which is raising fears in the ruling United Malays National Organisation (Umno) of political instability.

Mahathir, who is currently in Europe for a holiday, has vowed to continue his attacks on the government over a number of decisions in the face of what he says are efforts by UMNO leaders to demonise him.

Ministers and Umno members have in turn appealed to the feisty ex-premier to stop his public criticisms, while a minister has said he is trying to get a mediator to salvage crumbling relations between Mahathir and Abdullah.