"I am concerned about what individuals and what party will dominate the Senate. The Thai Rak Thai Party looks set to gain control over the new upper chamber," he said.

For yesterday's Senate race, many candidates had links to the ruling party, undermining their own credibility to implement non-partisan checks on the government, legislation and independent organisations, he said.

An appointed Senate would be more suitable for the country because a neutral panel would be in charge of nominating senators without government involvement, the former premier said.

The Senate election failed to achieve non-partisanship and the ban against soliciting votes did not pre-empt vote-buying as previously expected, he said.

Democrat Party leader Abhisit Vejjajiva called on incoming senators to join hands to restore the checks and balances via the new round of political reforms.

"People have become disillusioned with politics and it is imperative to quickly strengthen public confidence," he said.

Abhisit said incoming senators should uphold their integrity instead of letting vested interests cloud their judgement.

Outgoing Senator Kraisak Choonhavan expressed concern that about 170 of the 200 incoming senators may have ties, directly or indirectly, with the ruling party.