One of John McDonnell's senior Labour colleagues has said it's simply "irrelevant" to focus on his comments about Marxism.
Peter Dowd, shadow chief secretary to the Treasury, said it was more important to focus on Labour's tax policy than enter into a "political debate about 19th century economists."
He made the comments after shadow chancellor of the exchequer John McDonnell said there is a lot to learn from Karl Marx's Das Kapital.
Dowd spoke to Julia Hartley-Brewer about Labour's headline new tax initiative, which would only impose income tax rises on 5% of the population.
The interviewee told Julia that the burden of paying tax to fund our services should be placed on those who can most afford it. However he could not say whether other taxes would rise, stating that the plans will be revealed in the Labour manifesto.
He also added that the Tories have often made promises about tax which they have not kept, and people should pay more attention to this.
Listen to the full interview above