Speaking at a Communist event in London Susan Michie, a leading activist for the party, said that it was no longer putting candidates up against Labour.
At a meeting in London earlier this week, Professor Michie, whose ex-husband Andrew Murray was an aide to Jeremy Corbyn, told Communist members: “At the 2017 general election we decided not to contest in the election, and fully support Jeremy Corbyn, and the Communist Party of Britain (CPB) has agreed that supporting Labour is the priority and that it would be inappropriate to stand candidates.
“We will be out on the doorstep, putting forward the socialist arguments, and putting those forward in the Morning Star wherever possible in support of a left-led Labour party.
“This electoral policy is a potential springboard for strengthening organic ties with Labour. We can also use our significant influence in trade unions and campaigning organisations to show that Labour party policies will be closer to members interests than other electoral parties.
“We are in a really good situation to work much more closely that we have in the past. The Communist Party and the Labour left have much in common and have a track record of impressive joint working in trade union campaigns and elections.”
She added: “Communist Party members should absolutely be involved in electoral work, and working full tilt to get Jeremy elected as leader, and the Labour party into government.”
The comments have heightened concerns over the hard Left Labour leaderships links to the “insidious” Marxist ideology.
On 5 May, shadow Chancellor John McDonnell is due to speak at a 200th anniversary celebration of Marx’s birth under the title “Into the 21st Century: Marxism as a force of change today”.
In the past Mr Corbyn has also backed brutal Communist regimes in the Soviet Union, North Korea, Venezuela and Cuba.
Last night Tories said that the backing of British Communists had confirmed their worst fears about Mr Corbyn.
Romford MP Andrew Rosindell said: “This underlines the danger to Britain if Corbyn and his leftist allies ever win power.
“The links of the Labour leadership to Communists and their insidious ideology should frighten everybody.”
Mo Metcalf-Fisher of Conservative Progress added: “It’s sadly not surprising to see the Communist Party so eagerly endorse Jeremy Corbyn. Hard leftist factions, once bitter and confined to the political wilderness, are becoming increasingly comfortable with today’s Labour Party. This is a truly worrying development.”
Marion Smith, Director of the Victims of Communism Memorial Foundation warned that the philosophy of Marxism has created some of the greatest episodes of human suffering in all of history and should not be taken lightly.
He said: “Marxist states like the Soviet Union and communist China are responsible for more than one hundred million deaths as a result of their insane quest to implement Marx’s utopian ideas in practice.”
He added: “Every time Marxism is tried, it results in abject economic collapse or a repressive police state—or, as we are seeing right now in Venezuela, both.”