"Just like the incumbent senators, their successors will try to secure office by affiliating themselves with political parties," Senator Pichate Patanachote said.

Although senatorial candidates are banned from having official links to political parties, they have only 10 days to introduce themselves to voters, and that would be impossible without the support of canvassers, Pichate said.

Campaign ties between senatorial candidates and canvassers are bound to result in allegiances with either the government or the opposition, he added.

"In Nakhon Ratchasima I hear that party canvassers from government and opposition parties have started to sway voters in favour of would-be candidates," he said.

The Senate's term expires next month, and the senatorial election has been scheduled for April 19.

Another panellist, Pranot Nantiyakul, said that senatorial candidates should not try to sway voters in order to avoid associating themselves with political parties.

Pranot, training director at King Prajadhipok's Institute, said campaign rules for senatorial candidates were virtually impossible to enforce.

"The ban on partisanship is impractical because all senatorial candidates or their relatives have ties to political parties," he said.

Komson Phokong, a law lecturer at Sukhothai Thammathirat Open University, said the Senate should be disbanded because it had failed to serve in a non-partisan manner.

Sunisa Prawichai, of Bangkok University, said that in a poll he had conducted, almost half of those surveyed did not expect any improvement from the next Senate.

The survey of 3,183 people from 30 provinces, including Bangkok, also showed that 66 per cent had no confidence in the incoming senators upholding non-partisanship, Sunisa said.

Because of the mandatory vote, 83.7 per cent said they would cast their ballot even though they did not foresee the Senate changing for the better.