Scotland's First Minister Alex Salmond has been named Parliamentarian of the Year in the Spectator magazine awards.
First Minister Alex Salmond was praised for 'brilliant tactics'
Judges praised the SNP leader for a "brilliant" campaign in seizing power in the Scottish Parliament.
Shadow Chancellor George Osborne was named politician of the year for his plans to cut inheritance tax.
Former Prime Minister Tony Blair won the Resignation of the Year, while Newcomer of the Year went to Lib Dem leadership hopeful Nick Clegg.
The annual awards were presented in London by former Home Secretary John Reid, who won Politician of the Year last year.
Spectator editor Matthew d'Ancona said the Scottish elections had not just been a "kick in the teeth" for Gordon Brown, but "a moment in the annals of the Union."
In the May elections the Scottish National Party seized power at Holyrood, ending eight years of Labour rule.
"Suddenly the break-up of the United Kingdom is no longer a remote prospect," said Mr D'Ancona.
"Whatever your view on that great question, the judges felt it was right to salute the man whose brilliant tactics in the Scottish Parliament laid the foundations for an extraordinary victory."
Meanwhile, Mr Osborne was praised for his inheritance tax proposals, which have been credited with helping boost the Conservatives' opinion poll ratings and were followed by Mr Brown's decision not to call an early general election.
The judges said that "rarely, if ever, has a single policy proposal by an Opposition politician changed the political weather and shifted the political markets so spectacularly and so suddenly".
Three former Conservative leaders also won awards - Margaret Thatcher was Peer of the Year, William Hague gave the "Speech of the Year" and Iain Duncan Smith was Campaigner of the Year.
Minister To Watch was immigration minister Liam Byrne, while Inquisitor of the Year was Labour MP Michael Connarty, who chairs the Commons European Scrutiny Committee.
"Marathon Man of the Year" was Ian Paisley, after becoming First Minister In Northern Ireland at the age of 81.