Britain and Colombia are set to work on a series of measures aimed at ending a major supply route for the cocaine that ends up on UK streets.

At a Downing Street meeting on Wednesday with Colombian president-elect Alvaro Uribe, Tony Blair discussed ways of halting the trade of cocaine smugglers using Jamaica as a way of channelling drugs into the UK.

Jamaica, which comes under British jurisdiction, is used by Colombian drugs gangs as a major supply route into both the UK and parts of America. They are currently able to exploit the jurisdiction so that they cannot be arrested by the American Drug Enforcement Agency.

Relations between the two countries are currently strong, partly due to efforts to beat Colombia's drug trade and because of the arrest of three men with links to the IRA who are accused of training members of the left-wing FARC terror group.

The prime minister also urged Uribe to lift immunity on two officials working at the Colombian embassy in London so they can be questioned over the death of Damian Broom.

Broom, a warehouseman and father of one, was stabbed to death outside a supermarket in West London in May this year.

"The president-elect was asked to consider urgently the outstanding request to waive diplomatic immunity to the Colombians the police want to question," said the prime minister's official spokesman.

Diplomatic immunity is a convention of international law that means foreign government officials are not subject to the jurisdiction of local courts and other authorities.

The rules are set out in Vienna Convention on Diplomatic Relations of 1961 and the Vienna Convention on Consular Relations of 1963.

It means embassy workers are immune from criminal proceedings and they are not obliged to give evidence as a witness.

The last major diplomatic dispute was with Libya over the embassy officials who shot and killed WPC Yvonne Fletcher.

As Uribe does not take office until August 7, the matter remains as an issue for the current administration. If no agreement has not been reached by then, Uribe is likely to take a decision having been briefed by the UK government.