Prime Minister David Cameron said on Thursday (November 7) he will demand that Sri Lanka investigates allegations of war crimes and human rights abuses when he visits the country for a meeting of Commonwealth leaders next week.

Cameron, who met with Tamil campaigners, has had to defend his decision to attend the biennial Commonwealth leaders' meeting in the capital, Colombo. Cameron said he would have a better chance of securing changes if he pressed ahead with his visit to the former British colony.

Jan Jananayagam, Director Of Tamils Against Genocide, told reporters outside 10 Downing Street before a meeting with the prime minister that she hoped for a review of British foreign policy.

"I mean I will be expressing my organisations disappointment at the decision and that hopefully this is an opportunity for the prime minister to review the foreign office's policy to date," she said.

"I think that the prime minister, if he really wants to shine the spotlight on Sri Lanka, Sri Lanka's human rights, Sri Lanka's alleged war crimes and all of that, he has the chance to withdraw from this and send a lower level delegation and make the point even better," said Suren Surendiran, Global Tamil Forum Spokesperson And British Tamils Forum Senior Member.

Human rights groups have urged leaders to boycott the November 15-17 meeting to put pressure on the Sri Lankan President Mahinda Rajapaksa.

South African peace campaigner Archbishop Desmond Tutu said he supported a boycott, urging the world to "apply all the screws that it can".

The Sri Lankan government says its rights record has improved since the war and has rejected the criticism as unsubstantiated.

Presented by Adam Justice