Party briefing says candidate is closing gap on Labour opponent in Gorton seat that Gerald Kaufman held until his death

The Liberal Democrats are fast closing the gap on Labour in polling ahead of next month’s Manchester Gorton byelection and believe they could steal a victory to match their stunning success over the Conservatives in Richmond last December, according to an internal campaign briefing.

Only 45% of Labour voters think Corbyn would be best PM: poll Read more

Tim Farron’s party secured just 4.2% of the vote in the Manchester seat at the 2015 general election, coming fifth behind the Greens, the Conservatives and Ukip, as Labour cruised home with a majority of more than 24,000.

The contest, caused by the death aged 86 of veteran Labour MP Gerald Kaufman in February, was initially seen by Labour as a “comfortable hold” and by the Lib Dems as out of reach. It will take place on 4 May.

But a briefing for senior Lib Dem officials and campaigners – written by deputy director of campaigns Dave McCobb – says the party’s messages on Brexit, including calls for a second referendum on the outcome of negotiations, are winning over voters in a seat where more than 60% voted remain in last June’s Brexit referendum.

McCobb says the Lib Dems are making up ground fast and are on 31%, with Labour on 51% – a level of support that is, he says, “running well ahead of where we were in the Witney byelection [where the party leapfrogged Labour and Ukip to come second in October last year in David Cameron’s former seat] and approaching Richmond Park levels of support at this stage.”

Many Labour remain voters, he says, are angry at the party’s support for triggering article 50 and concerned at the state of the party under Jeremy Corbyn.

Labour sources who have campaigned in the seat say they are still confident that their candidate, Afzal Khan – a solicitor and MEP for the north-west of England since 2014 – will win but accept that the Lib Dem candidate, Jackie Pearcey, a former councillor in Gorton, is making up ground. Former Labour MP George Galloway is standing in the seat as an independent.

The byelection will take place on the same day as local elections in which Labour is, according to independent analyses, expected to lose seats and control of key councils including Glasgow.

Voters will also elect mayors in Greater Manchester, the Liverpool city region, the West Midlands, Tees Valley, the West of England and Cambridge and Peterborough.

The latest Opinium/Observer poll offers some better news for Corbyn’s party nationally, showing Labour has closed the gap with the Tories by four percentage points over the last month to nine percentage points.

The Tories are on 38% (down three), Labour 29% (up one), Ukip 14% (up one) and the Lib Dems on 7% (down one).

But only 45% of Labour supporters now believe that Jeremy Corbyn would make the best prime minister. Just 17% of all voters trust Labour most to run the economy against 45% for the Tories.

About 40% trust the Tories most to manage Brexit negotiations and the UK’s future relations with the EU, against 11% who trust Labour most.