They say a week is a long time in politics, but it is hard to believe that parties have now been on the campaign trail for over 3 weeks. 

Boris Johnson and the Conservatives have a commanding lead in the polls as the general election campaign wraps up its third week.

Depending on your pollster, the Conservative leads are as varied with Boris Johnson enjoying leads between 12-19 points, with a poll from Datapraxis suggesting Boris Johnson’s party would pick up an extra 57 seats, taking it to 355 and giving the Prime Minister a comfortable Commons majority of 48 seats. 

The latest YouGov poll also suggested Boris Johnson would secure a majority in the Commons.

If the election were held this Thursday, YouGov's constituency by constituency poll for The Times puts the Tories on 359 seats, up 42 on their 2017 performance, while Labour would lose 51 seats to 211 and the Lib Dems would gain just one to secure 13 constituencies.

You can see their estimate for each constituency by clicking here

With so many polls and so much to take in from the campaigns it is hard to gain an insight into whether anything has changed. 

In a bid to show the difference since campaigning began, we have looked at two separate PA polls more than three weeks apart to see if there is any notable difference.

The aggregate poll shows the average polling numbers for each party from a number of sources to try and show the voting intention. 

It is important to note that PA does not take into account Scotland only polls - using only UK wide data - therefore the SNP has not been included in the graph from the Press Association. 

The two polls in this article show the voting intention from the end of October to the start of November (video 1) and the voting intention from 18-25th November (video 2) 

Video One - Voting intentions from Oct 30 - Nov 5th

It suggests a growth in support for the Conservatives coupled with a decline in support for the Brexit Party following the decision by Nigel Farage’s Brexit Party to give the Conservatives a free run in Tory-held seats.

The average polling dating from November 18th - 25th shows a 3% decrease for Labour in comparison to polling between 30th October - 5th November. 

Video 2 - Voting intentions from November 18th-25th 

It also indicates a UK wide decrease in support for the Lib Dems with the latest Ipsos MORI poll showing support for Jo Swinson’s party has dropped by 4% between October and November. 

Support for the Green Party across the UK has remained the same. 

While the polls give an indication of the UK voting intention, Boris Johnson was subject to a grilling in what many called a "car crash" performance on BBC Question Time. 

Over the weekend, a Scotland poll from Panelbase showed the SNP could see their seat count rise from 35 to 41, with support rising from 37% to 40%, while Labour faced being wiped out in Scotland. 

With two weeks until election day, a number of debates to be conducted there is still ample time for public opinion to shift - just as it did away from Theresa May in 2017.