Prime Minister Abhisit Vejjajiva yesterday said Cambodia should stop interfering in Thai affairs, after its leader Hun Sen stepped into the debate over the government's decision to leave the WHC.

Hun Sen has challenged the government to officially inform the United Nations Education, Scientific and Cultural Organisation (Unesco) if it was serious about withdrawing.

Political commentators have criticised the government for showboating over the issue to attract the support of voters allied to the People's Alliance for Democracy, who have campaigned for the government to withdraw from the WHC to safeguard Thai territory in the disputed border area.

Natural Resources and Environment Minister Suwit Khunkitti, who walked out of a WHC meeting in Paris last week, has been forced to defend his decision amid claims that it discredits the country internationally.

He said the government would discuss with UNESCO the effects of the WHC's decision not to consider Cambodia's management plan for Preah Vihear temple.

The matter concerned Thailand and Unesco only, Mr. Abhisit said. He insisted the government's decision to withdraw from the WHC was meant to protect Thai territory, and not done merely for domestic political advantage.

Thailand has yet to formally withdraw from the body, despite Mr Suwit's assertion from Paris last week that his withdrawal took immediate effect.

The government had campaigned against the WHC discussing Cambodia's management plan for the disputed Preah Vihear temple, and threatened to withdraw if the plan was put on the agenda.

Sources say the meeting was drafting a statement confirming that discussion of the plan would be postponed, which was in line with a decision reached at an earlier WHC meeting in May.

However, the Thai delegation took exception to the wording of the draft, so Mr Suwit walked out.