Opinium’s figures for the Observer say although the Conservatives still have a 12-point lead, the opposition is gaining support

Labour has cut the Conservatives’ poll lead after a week dominated by gaffes, controversies and resignations from the two main parties, according to the latest survey by Opinium for the Observer.

The Tories still hold a 12-point advantage over Labour but their lead is down four points since last weekend. The Conservatives now stand on 41%, down one point on a week ago, while Labour is up three on 29%.

The Liberal Democrats are down one point on 15%, while the Brexit Party has fallen sharply by three points in a week to 6%, since party leader Nigel Farage announced he would not stand as an MP.

Opinium’s latest data suggests Labour may be stemming the flow of both Labour Leavers to the Tories and Remainers to the Lib Dems.

Some 66% of Labour Leavers now plan to vote for Jeremy Corbyn’s party on 12 December, up nine points compared with a week ago.

Similarly, 48% of Labour Remainers are planning to vote for the party, sharply up on last week.

Boris Johnson is still the most popular choice for prime minister. Currently, 38% think he would make the best occupant of Downing Street, up one point from last week. Some 18% think that Jeremy Corbyn would be the best prime minister, his best score since August.

Only 31% are actively satisfied with Boris Johnson, while 20% are dissatisfied with him but prefer him to Jeremy Corbyn. By comparison, at the end of the 2017 general election campaign, 35% were satisfied with Theresa May, while 18% were dissatisfied with her but preferred her to Jeremy Corbyn.

Opinium said that there had been some changes among Leave voters that brought their opinion of the two main leaders more in line with their views before the 2017 election. The proportion of people saying they are satisfied with Johnson dropped seven points to 53%. The proportion saying that they prefer Corbyn has risen by two points to 10%, with those saying they don’t know also increasing.

Adam Drummond, head of political polling at Opinium, said: “There are some signs that a 2017-style squeeze is taking shape with some Labour voters coming home and a relative lack of Brexit news looks like it’s helping Labour Leavers return to the fold.

“The Brexit party has continued to decline and partisan feelings are starting to assert themselves in views of Nigel Farage, whose approval rating among Leave voters has dropped since he started attacking the Tories.”