The Sun, which dropped the Conservatives to back Labour in 1997 and 2001, has announced that it is still considering which party to back at the election.

The Sun, which dropped the Conservatives to back Labour in 1997 and 2001, has announced that it is still considering which party to back at the election.

In a front-page leader, Britain's best-selling newspaper told its readers: "Like so many of you, our mind has still to be made up." The announcement, which comes after the paper has moved towards the Conservatives on a range of issues from crime to immigration, cheered aides of the Tory leader, Michael Howard, but the paper left the door open to backing Labour on polling day.

Tony Blair assiduously cultivated the Rupert Murdoch press in the run-up to the 1997 and 2001 elections.

One Tory aide said: "It's encouraging for us. They have backed us on some issues. It is interesting that they have decided to make this statement."

Labour acknowledged that the election would be "very, very hard work". One source said: "We know we will have to convince people who read The Sun they should vote for us. We are facing a tough battle. It won't be like 2001, it will be difficult and we know that."

The paper, which sells 3.2 million copies, said: "In many ways the Conservatives speak our language." But it also warned that many members of the Shadow Cabinet "leave the voters cold".

The paper said Labour's record "is a mixture of successes and awful blunders", heaping praise on the party's stewardship of the economy, but criticising the Government for failing to reform public services.

It said it "discounted" the Liberal Democrats as "unprincipled and unworthy of your vote". The Sun, whose readers include a politically crucial audience of skilled, working-class voters, helped sweep Margaret Thatcher to power in 1979, bitterly attacked Neil Kinnock and claimed that it was " The Sun wot won it" for John Major.

The paper was ruthlessly cultivated by Mr Blair's former communications chief Alastair Campbell in the run-up to the 1997 general election, when its conversion to Labour under Mr Blair was a devastating blow for Mr Major.