It can be longer - Conservative former PM John Major called the 1997 general election eight weeks before polling day.

BBC: 'More notice' call for elections

In a nationwide address before the polling began, General Musharraf promised to relinquish some executive responsibilities to a newly appointed prime minister, but to retain key powers, such as the ability to dismiss parliament.

ECONOMIST: After the vote

The general election game plays out the polling battle on a computer controlled board that is part-Monopoly, part-Trivial Pursuit.

BBC: Playing the politics game