The Christian student leader of the pro-democracy protests has begun a hunger strike, defying calls from other protest leaders to retreat.

Joshua Wong, 18, leads the student activist movement Scholarism, and is joined by two other members of the movement in a last-ditch attempt to make themselves heard, the Times reports.

The protests, which are calling for more democratic elections without interference from Beijing, have been going on since September, in Admiralty, Hong Kong.

But the demonstrations have taken a turn for the worse in recent days, as protestors surrounding the government buildings clashed with police on Sunday, leading to 40 arrests and numerous casualties.

Some protesters are now beginning to admit that they have failed, particularly following Sunday's more violent demonstration.

Leader of the Federation of Students, Alex Chow Yong-kang, told the South China Moring Post: "...as a whole, it was a failure. The whole plan did not achieve its objective of paralysing government." He admitted that there was a difference of opinion on strategy between the various groups.

Three leaders of the Occupy Central movement have today handed themselves into the police in a show of commitment to the rule of law, and encouraged the students to withdraw amid fears of further violence.

Benny Tai, Chan Kin-man and Reverend Chu Yiu-ming were accompanied by Cardinal Joseph Zen, the former Catholic Bisho of Hong Kong as they went to the police station this morning. They were permitted to leave without any charges.

"I hope we can show others the meaning of the surrender. We urge the occupation to end soon and more citizens will carry out the basic responsibility of civil disobedience, which is to surrender," said Benny Tai, the most prominent Occupy leader, after he left the police station, Reuters reports.

Defending his position, Wong and his fellow strikers wrote on Facebook: "Living in these troubled times, there is a duty. Today we are willing to pay the price, we are willing to take the responsibility. Our future, we will take it back."

The protests, which are focussed on the 2017 election of Hong Kong's chief executive, have been branded illegal by the Chinese government.

Wong was charged last week with obstructing a public officer, and has been released on bail awaiting his trial in January.