Court secretary-general Chaovana Traimas said the court judges ruled 6:2 that the bill is also unlawful because some lawmakers voted on behalf of others who were absent from the parliamentary session.
Mr Chaovana said the Constitution Court judges also agreed to accept the petition of the Election Commission (EC) on the conflict between the agency and the caretaker government on holding polls for 28 southern constituencies where there were no MP candidates.
The court also accepted to consider the petition of Kittipong Kamolthammavongse, a Thammasat University lecturer, who alleged that the Feb 2 election was unconstitutional as it was not organised on a single day nationwide as stated in the supreme law and that it resulted in unfair treatment to candidates.
Caretaker Prime Minister Yingluck Shinawatra today refused to comment over the court’s ruling, saying she needs to study it first.
Ms Yingluck however reportedly shared a Facebook note on the status of her caretaker Finance Minister Kittiratt Na Ranong, saying that "The government has tried its best to push forward the investment in basic infrastructure, particularly on transportation system, paving the way for Thailand's better future."
Mr Kittiratt's comment also expressed regret for the decision to drop the 2 trillion investment project, saying Thailand will lose its opportunity in the fast changing world.
Prior to the court ruling, caretaker Transport Minister Chadchart Sittipunt said he was ready to accept and follow the court’s ruling no matter what the result.
He said that confidence in government will not be affected following the court ruling, but rather, investor's confidence will be dampened for fears of the country's delayed development.
Mr Chadchart noted that although the bill is considered unlawful, the government can still proceed with the infrastructure development project through loans via public debt bill, project by project.
Regarding the demand of opposition Democrat Party that the government takes responsibility following the court's ruling, Mr Chadchart said there's no need to do so as the government has done its best and the bill has already been approved in parliament.