Only 45 per cent of Labour voters think Jeremy Corbyn would be the best choice for Prime Minister, according to research conducted by Opinium for the Observer.
The Conservatives remain the most trusted party on all key issues polled - except for the NHS, where Labour was the more trusted party by eight percentage points on 28 per cent.
In a two-way choice between Corbyn and Prime Minister Theresa May, 47 per cent would opt for May and only 14 per cent for the opposition leader.
Fewer than half of Labour voters, 45 per cent, wanted to see Corbyn take the helm.
However, 28 per cent of all respondents said they wanted neither Corbyn nor May.
The Conservatives lost their double-digit lead over Labour in headline voting intentions, but were still nine percentage points ahead, in the poll of more than 2,000 adults above the age of 18.
The news comes a day after the Conservatives won a council seat from Labour in Middlesbrough, traditionally a stronghold for the current opposition party.
In a survey conducted last month, just 44 per cent of Labour members said Corbyn should stay to fight the next General Election, while just over a third said he should back down "immediately".
Divisions within the party have not stopped the leader from announcing a slew of new policies in the last few weeks. On Thursday, Corbyn announced a plan to upgrade the economy that included only granting public procurement contracts to companies that give full recognition to trade unions and have a 20-1 pay ratio.
Last week, Labour unleashed a charm offensive for small businesses by declaring a "war" on late payments to suppliers that hold smaller firms back, as well as promising free school meals for all primary school students earlier this month.