His comments came amid calls for him to veto the legislation. The rightist People’s Party on Wednesday called a news conference announcing that it had voted against the bill and would try to reverse it; another party, People-Animals-Nature (PAN), which has one seat in parliament, also opposed the bill.

In a statement released late on Wednesday morning, the president noted that he was not yet allowed to pronounce on the bill, and wrote that: “During this period of eight days and after notification by the Speaker of Parliament, the Prime Minister and one fifth of serving deputies have the right to request a preventive review of the constitutionality of the legislation.”

According to the statement, the president received the legislation, which was approved by parliament on 21 December, the following day, and is not allowed to pronounce an opinion on it until eight days after receiving it.

Last Thursday the president had said that he did not know the details of the party finances beyond that it involved a "fundamental alteration" in the model of oversight that had been requested by the Constitutional Court, and said that he would examine the text that evening. He stressed that "there was an alteration that had to be made, a fundamental one, which was a basic alteration requested by the Constitutional Court to observe the Constitution in overseeing the accounts.

"That was the major basic alteration,” he said. “If there are other detailed alterations, I’ll take a look.”

Asked by journalists whether he might ask the Constitutional Court to rule on whether the changes were constitutional, he said only that he had not yet read the text.

Parliament on 21 December approved, by email vote, changes to the law on financing of political parties, with the People’s Party and PAN voting against on the grounds that they disagree with the planned abolition of a ceiling for fund-raising.

For more than a year the president of the Constitutional Court has been asking parliament to alter the oversight model for party finance by setting up a panel to appeal against decisions taken. Under the new legislation, the Entity for Political Accounts and Financing (ECFP) is to be responsible for overseeing the accounts, with the power to fine offenders; if the parties disagree they can appeal a decision to the Constitutional Court.

However, in addition to this and other procedural changes, the governing Socialist Party, the Communist Party, the Left Bloc and the Greens agreed in changing other rules on party financing, including an end to the existing ceiling on funding and the extension of exemption from value-added tax of all party activities.

At present the parties can claim back VAT but only for activities directly related to propaganda.

The proposed changes, which were voted through over a holiday period when most people are not focussing on political issues, have triggered an outcry on social media.

In the meantime, the Left Bloc has said that it opposed the changes relating to VAT but had voted in favour because of "the need for consensus". In a statement on Wednesday, it said that the bill "could and should improve".