Is this the last battle for Sri Lanka's 'warrior king'?

As Sri Lanka prepares to go to the polls next week, the country's controversial former president, Mahinda Rajapaksa, is fighting a battle for his political life.

He has faced a dizzying reversal in his fortunes.

This is the man who presents himself as the warrior king who, in 2009, ended the island nation's 26-year-long civil war.

The country's Tamil minority paid a terrible price for his "victory". One UN report estimates that 40,000 Tamil civilians were killed in the last few weeks of the war.

But finally putting an end to years of conflict proved hugely popular with the majority Sinhalese population and Mr Rajapaksa and his family seemed set to run Sri Lanka for decades to come. He ended the two-term limit for president and appeared to be grooming his eldest son for power.

That all changed in January when, in a betrayal worthy of a Shakespearean drama, Mr Rajapaksa was unseated.

His uncharismatic health minister Maithripala Sirisena unexpectedly won a narrow majority in the presidential elections, standing against his former political master.

Mr Sirisena's win was seen as a major change in Sri Lankan politics

But Mr Rajapaksa is back, now standing not for president, but to be a humble MP - although he says he expects his party to do well enough to ensure he will become prime minister.

When I spoke to him in the kitchen of his huge house in the Sri Lankan capital Colombo, he told me he was only running by popular demand.

"They want me," he said. "I thought I'd retired but when I went back to my village, you should have seen the queues! There were over 100,000 people."

That may be so, but there are other compelling reasons for Mr Rajapaksa to want to return to power.

Mr Rajapaksa (centre) is contesting to be an MP in the Kurunegala district in north west Sri Lanka

Since he lost the presidency, his reputation has come under attack. Members of his inner circle have been accused of graft, abuse of power and even murder. They deny the allegations.

Meanwhile Mr Rajapaksa, the self-styled father of the new Sri Lankan nation, is alleged to have been involved in corruption on an epic scale.

He told me he was a victim of smears put about by his opponents.

"This is all political tricks," he insisted when we spoke. "Politically they want to attack us so they will do that."

I asked about the allegations that billions of dollars had been stolen during his time in power.

"So why don't you help us find this money?" he barked angrily, as his entourage swept the visibly irritated former president out of the house and into a waiting Mercedes.

He was more forthcoming at a huge rally just outside Colombo.

Mr Rajapaksa's rallies have drawn large crowds

His effort to become an MP is being run as if he was still a presidential candidate. Before he takes to the platform there are endless speeches by fawning supporters, songs extolling his many virtues, and swooping cameras to project images of his cheering fans onto vast television screens.

He told the crowd the real corruption is in the new government, citing an alleged scam involving the sale of government bonds.

He also warns that the current government's plans to devolve power to the Tamil north will split the nation in two.

But it isn't clear he has the attention of some of his key supporters. During his speech I watched as one of the dignitaries on the podium behind him slumped forward gently and nodded off.

And his arguments seem to be falling on deaf ears amongst the public too. He's expected to win his parliamentary seat comfortably but a recent opinion poll suggests his party is trailing significantly behind the government.

Nevertheless it would be wrong to write the old warhorse off quite yet.

The fact that he is standing at all is testament to this veteran politician's tenacity, and the huge turnout at his rallies shows he still has some passionate supporters.