Surveys undertaken during the row over the funding of the PM’s flat refurbishment and lobbying appeared to show little change in the numbers, with a BMG poll conducted for The Independent last week showing support for Mr Johnson’s party had even increased.
However, new figures from pollsters Opinium show the Conservative Party lead over Labour fall dramatically from 11 points to just five points, with Mr Johnson’s party on 42 per cent compared to 37 per cent for Sir Keir Starmer’s Labour.
And the favourability rating for the prime minister, which had been riding high following the success of the vaccine rollout in the UK, also took a dent.
The survey of 2,000 voters undertaken for The Observer found Mr Johnson’s net favourability stood at -6 compared to the Labour leader, who was on +8.
The numbers represent a decline for Mr Johnson and a growth in support for Sir Keir, with both men having been tied at a favourability of +1 last week.
Meanwhile a poll by Focaldata of 1,555 people for The Sunday Times put the two main parties much closer, with the Tories holding 40 per cent support to 39 per cent for Labour.
It also found Labour inching ahead among the so-called red wall voters in northern areas that had previously been Labour strongholds but fell to the Tories in 2019.
The poll suggests Labour holds 45 per cent support in the region to the Conservatives’ 44 per cent.
Thursday’s elections mark the first electoral challenge for Sir Keir after having taken over the party leadership from Jeremy Corbyn.
It also marks the first test of public opinion for Mr Johnson’s party during the fallout of the coronavirus pandemic.
In addition to the English local and Scottish and Welsh elections, there is a Westminster by-election for Hartlepool, which has been held by Labour since 1964.