Two big UK tobacco companies have failed to persuade the high court to strike out a case against them that alleges they are responsible for the exploitation of Malawian farming families and child labour in their drive for profits.

British American Tobacco and Imperial Tobacco deny the allegations. They argued that the Malawian families could not prove that the tobacco they grew had ended up in their cigarettes.

The farmers’ lawyers said they had repeatedly asked the companies for proof that they had not bought tobacco from their clients, but no documents had been disclosed to them.

In the high court, Mr Justice Martin Spencer said the companies’ application to strike out the case had been “misconceived”. The judge said lawyers for the farmers were not required to offer proof at the beginning of a legal action, only when it came to full trial...

The lawyers argue the conditions of work breach the definition of forced labour, unlawful compulsory labour and exploitation under Malawian law...

In their literature, the companies claim they can trace where their tobacco comes from “down to farm level” and they monitor conditions on those farms.

However, in his judgment, the judge referred to correspondence in which BAT admitted that “traceability down to the farm level” did not actually mean it could trace tobacco to individual farmers working their separate fields...

A spokesperson for Imperial said they could not comment further because the litigation was ongoing, “other than to reiterate that we will continue to defend the claim”.

BAT said it had “a longstanding commitment to respect the human rights of our employees, the people we work with and the communities in which we operate. We will continue to vigorously defend the claims and we are unable to provide further comment while this case continues.”