A number of fixtures look set to be targeted by demonstrators who claim that the tour is offering succour to the regime of Zimbabwe president Robert Mugabe.

Lamb told BBC Radio Five Live: "It upsets me when people say we are putting money before morality.

"I think there are double standards here. It is unfair for cricket to have to make political decisions."

Lamb insists the tour is going ahead for cricketing reasons but the financial implications of pulling out would be damaging.

He added: "We don't think the Zimbabwe cricketers are any more the henchmen of Robert Mugabe than the England players are the foot soldiers of Tony Blair. They are representing their country at cricket.

"Let me stress that the Zimbabwe Cricket Union who sanctioned this tour is an apolitical organisation. Its staff are drawn from a variety of the country's ethnic backgrounds."

"We need to generate revenue to do the things we do from the playground to Test arena and without the money from the Test arena we can't do those things."

Lamb does not have a problem with people using their right but appealed for people to protest peacefully.

"We live in a country where people can express their views," he added. "But we are also lawfully playing cricket and I hope whilst people can express their views we can play the games unhindered."