Thai Prime Minister Yingluck Shinawatra begged anti-government activists to end their protests shortly before cruising through a no-confidence vote.

Opposition leader and former deputy PM Suthep Thaugsuban has repeatedly rejected calls for negotiations and accused Ms Yingluck of being a puppet of her brother, former PM Thaksin Shinawatra.

Ms Yingluck urged protesters: "Please call off the protests, for the country's peace.

"I'm begging you ... because this doesn't make the situation any better."

She said the occupation of several ministries had failed to shut down the government but had created the potential for violence.

Ms Yingluck has been wary of using force against the protesters for fear of sparking bloodshed that could harm the tourist industry and investment.

Demonstrators laid siege to the police headquarters yesterday, even cutting its water and power supply as lines of riot police stood idly inside.

Mr Suthep served as deputy to Abhisit Vejjajiva from 2008-11. In 2010, a crackdown on anti-government protests by pro-Thaksin red-shirt activists resulted in more than 90 deaths.

Ms Yingluck was elected in the wake of the violence, maintaining a testy relationship with the military that toppled her brother and consigning Mr Suthep to opposition.

He quit the Democratic Party this year to lead protests against a political amnesty bill that many fear would enable Mr Thaksin to return to Thailand without facing jail for corruption charges.

Mr Thaksin has been holed up in Dubai to avoid the charges that he claims are politically motivated.

The billionaire was toppled in a 2006 coup for alleged corruption, abuse of power and insulting the king but had won over the rural poor with a number of populist reforms.

The opposition claims Ms Yingluck's landslide 2011 win was illegitimate as she was bankrolled by her sibling.

The protests have dwindled since a 100,000-strong demonstration on Sunday, with a few thousand now occupying the Ministry of Finance and other offices.

Ms Yingluck dismissed the protests as "symbolic."

She said: "In reality, we can still work ... the bureaucracy can still run."