The legal benchmark for electoral expenses had been in place for the past 25 years and could not "suddenly become wrong", Prime Minister Lawrence Gonzi said yesterday.

During a radio interview, Dr Gonzi said he agreed with the position taken by MEP candidate Roberta Metsola Tedesco Triccas, who on Saturday said she believed the law capping how much European Parliament election candidates spent on their campaigns applied from the minute she officially became a candidate through her registration with the electoral commission.

The law says that EP candidates cannot spend more than €18,000, but while at least two unelected candidates admitted they had gone beyond this threshold, all of the elected MEPs took an oath that they had kept within this limit during June's election - raising the question of whether they had taken false oaths, given the lavish spending seen by some of them. But if the interpretation of Dr Metsola Tedesco Triccas is accepted, it would mean that candidates' spending before the registration could be excluded.

The Prime Minister said she was right in her interpretation and added that something which existed for 25 years "cannot have suddenly become wrong".

However, he referred to a joint letter sent on Saturday by himself and Opposition Leader Joseph Muscat to the Speaker of the House, urging the Select Committee to discuss and revise the law.

"There are certain defects in the law which need to be amended, but only by people who are competent," he said.