With less than three weeks to go until polling day, the Conservatives' lead over Labour has been steadily narrowing.

The Independent's poll tracker, which charts the overall trend by taking an average of all mainstream polls, shows Theresa May's party still commands a 7-point lead.

However, the Labour Party has increased its average rating by nine points since the Prime Minister called a snap election, to 36.3 per cent - their best showing in the polls since November last year.

Some early polls had the Tories at almost double the vote share of the Labour Party. However, the Tories' lead has shrunk since the party's so-called "dementia tax" announced in its manifesto launch on 18 May.

YouGov research conducted between 22 and 23 May found the proposed change to social care was the Conservatives’ most memorable policy.

On the other hand, the Labour policy which voters recalled most often was its pledge to scrap tuition fees.

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The Conservatives are still on course to increase their current working majority of 17. Electoral Calculus predicts that, with 47 per cent of the vote, the Conservatives would win 387 seats.

If Labour secure 31.2 per cent of the vote, that would equate to 189 seats, according to Electoral Calculus. That share of the vote would be higher than the 30.4 per cent that Ed Miliband received in 2015, but the party's number of seats would drop from the 232 elected in 2015 to 185.