Tens of thousands of anti-government protesters marched through the streets of Thai capital Bangkok on Saturday.

After a recent lull in campaigning, they were trying to revive a campaign forcing Prime Minister Yingluck Shinawatra to resign.

Her opponents have blocked Bangkok’s major roads, stormed government offices and most recently transformed Lumpini Park into a protest headquarters overrun with tents and sleeping bags.

Saturday’s crowds marched from the park to the city’s historic quarter to press demands that the government yield power to an unelected council.

Several hundred forced their way into the prime minister’s office compound in a symbolic show of defiance.

The compound has been largely deserted by officials since the protests started.

The march was the first major rally since the Constitutional Court ruled on March 21 to nullify last month’s general election, a ruling cheered by protesters and criticised by government supporters as the latest sign of judicial bias.

Ms Shinawatra’s Pheu Thai party had been expected to win in February, especially because the opposition Democrat Party boycotted the election.

Election officials say it will now take at least three months for a new vote to be held.

The Prime Minister will appear before the National Anti-Corruption Commission today to submit her defence against charges that she was mainly responsible for a failed rice-subsidy scheme that cost the government millions.

If the commission decides to indict her and forward the case to the Senate for an impeachment vote, government supporters have vowed to rise up in her defence.

The current Senate is pro-Shinawatra, but that could change as the votes are counted in yesterday’s election to fill 77 seats in the 150-seat body.

The remaining seats are appointed and a government attempt to make the Senate fully elected was one of the triggers for the unrest that started in November.

Government red shirt supporters have vowed to stage their own mass rally next Saturday.