As the Constitutional Court has rejected the Election Commission's (EC) petition seeking a ruling on the calculation method for party-list MPs, the poll agency could be sued by political parties that are disadvantaged by any formulas it has devised, pundits say.
Jade Donavanik, a former adviser to the Constitution Drafting Committee (CDC), told the Bangkok Post the EC had hoped the charter court would rule on the matter.
However, as the court refused to accept the petition, the EC is on its own, he said.
"The EC must step up to the task and come up with a formula that adheres to the principles contained in the charter, as well as the organic laws governing the election of MPs," said Mr Jade.
The former CDC adviser said that if the EC comes up with a formula that favours smaller political parties which had failed to meet the parliamentary threshold under the mixed-member proportional (MMP) representation system, larger parties would immediately lodge complaints against the poll agency, he said.
"They would accuse the EC of abusing its powers or even negligence," said Mr Jade, before adding that the reverse is true if the poll agency comes up with a formula that favours larger parties.
"I feel sympathy towards the EC," Mr Jade added.
Acting deputy leader of the Democrats, Satit Pitutacha, told the Bangkok Post that from now on, the EC must tread carefully in interpreting the law to formulate its calculation method.
"The EC cannot be biased towards any political party," Mr Satit said.
Sawaeng Boonmee, deputy secretary-general of the EC, said the poll agency will have to come up with its own formula to calculate party-list MPs by May 9, as the agency is required to officially endorse and announce the result of the March 24 election on that date.
"If we can't do so, we would be breaking the law," Mr Sawaeng said.
He said that the EC has already come up with a method to calculate the number of party-list MPs, and that the calculations can be done in "less than five minutes".
The Constitutional Court on Wednesday refused to weigh in on the matter and rejected the EC's petition.
There are two laws which stipulate how the 150 party-list seats should be distributed, namely Section 91 of the constitution and Section 128 of the organic law governing the elections of MPs.
Sticking to Section 128, the EC had previously stated it wants the court to rule on whether it can calculate the party-list seats in a way that would award them to parties that garnered fewer votes than required under the MMP representation system.
However, critics said Section 128 of the organic law goes against the principles contained in Section 91 of the charter. The EC also petitioned the court to rule whether this section contravenes Section 91 of the constitution.
The court on Wednesday ruled 7-2 that it is the duty and power of the EC to iron out the calculation method in line with both Section 91 of the charter and Section 128 of the organic law.
In its ruling, the court said that the EC has yet to show that it has performed its duties and/or exercised its powers under the constitution.
Regarding the petition asking the Constitutional Court to rule whether Section 128 of the organic law runs afoul of Section 91 of the charter, the court said the EC cannot petition this directly to the Constitutional Court without going through the ombudsmen or the courts of justice first.
Whatever formula the EC settles on will have an impact the formation of the coalition -- which has essentially turned into a competition between the Pheu Thai Party and its seven-party alliance, and the pro-regime Palang Pracharath Party (PPRP).
The EC said its calculation method would make it possible for small parties that garnered between 30,000-40,000 votes to earn at least one seat.
Political pundits said this method is likely to favour the PPRP and its allies in the race to form a coalition government.