Republican switches party

US Republican Senator Arlen Specter is to switch sides and become a Democrat.



The move will give the Democrats 59 votes in the US Senate, just one short of the 60 needed to overturn Republican attempts to block legislation.



The Democrats are expected to pick up their 60th vote when the result of the still-disputed Minnesota Senate race is decided by the courts.



US President Barack Obama, a Democrat, is reported to have called Mr. Specter after he was informed of the switch to tell him that he was thrilled to have him in his party.



Specter, who is 79 was reportedly facing a tough challenge from conservative Pat Toomey in a primary election to decide, who would run as the Republican candidate for the Pennsylvania Senate seat in 2010.



Polls have suggested that Specter's decision to vote for the president's economic stimulus package earlier this year had been unpopular with Republican activists in the state.