Uribe, who won the election with 62 per cent of the vote, said the court was trying to pressure his government, pick and choose where it applies justice and erode presidential powers with its rulings.

"This high court's justices have lent themselves to a power [struggle] which seems not to have a legal solution," the conservative leader said in a nationally televised address on Thursday.

Paramilitary 'links'

Medina has said that Uribe was aware of the bribes, though the president and his ministers have denied any wrongdoing.

Colombian paramilitaries are accused of
targeting trade unions [AP]
But the votes of two legislators, Medina and another - Teodolindo Avendano, who was also arrested over the bribery allegations, helped push the election bill through.

The scandal - and Uribe's response - have upset local financial markets and could further complicate the passing of a trade deal with the US, despite Colombia being the White House's closest ally in Latin America.

The scandal comes on top of investigations linking some of Uribe's closest congressional allies to paramilitary death squads.

Dozens of members of his coalition are accused of using death squads to intimidate voters.

Popular president

Carlos Gaviria, a left-wing challenger to Uribe in the 2006 poll, said Uribe was "a dictator using the army or the police as a means to make things happen the way he wants them to happen".

And senator Gustavo Petro, of the left-wing Democratic Alternative Pole party, accused Uribe of "buying lawmakers to secure a particular interest."

However, with his popularity approval ratings running at 80 per cent, according to opinion polls, analysts said Uribe could easily win another election and extend his time in office.

"This is his way of taking the momentum back from the court. It's a brilliant counterpunch," said Mauricio Romero, a political science professor at Bogota's Javeriana University.