Why Tony Blair delayed his plan of announcing the election campaign?

The British Prime Minister Tony Blair is expected to end months of speculation today by announcing the date of the general election. According to tradition he would first go to Buckingham Palace to ask Queen Elizabeth to dissolve parliament. It’s widely anticipated that the election will be held on May 5.
     Many had expected the British Prime Minister to announce the start of the election campaign on Monday. But following the death of Pope, Tony Blair delayed his plans. The main theme of this election will be the state of Britain’s public services, immigration and economy. Public opinion polls suggest Mr. Blair is on course to win a third term in office. But the main opposition parties, the Conservatives and Liberal-Democrats, are both hoping to exploit what they believe is a lack of trust in the government.