KUALA LUMPUR— Malaysian authorities ordered former prime minister ­Mahathir Mohamad’s political party to temporarily disband Thursday in a blow to the opposition ahead of an expected general election.

The Registrar of Societies said the Parti Pribumi Bersatu Malaysia failed to submit adequate documentation for its registration and asked it to do so within a month or be permanently deregistered.

Elections are due by August, but Prime Minister Najib Razak is widely expected to dissolve Parliament on Friday to pave the way for a vote next month. Support for Najib’s ruling coalition has dwindled in the last two elections, and in 2013 it lost the popular vote for the first time.

Mahathir, called the order tyranny and unconstitutional because the party had given all the documents to the registrar.

Mahathir, 92, said the party will appeal to the home minister, and if that is unsuccessful, it will file a legal suit challenging the order. He said the move was aimed at preventing Pribumi from contesting the election and at blocking the registration of the opposition alliance as a united front.

ASSOCIATED PRESS