Bernie Sanders seeks money from donors to fund delegates' trip

Bernie Sanders' presidential campaign has asked supporters for donations, saying it was up to them whether pledged delegates could afford trips to Philadelphia next month for the Democratic National Convention.

In an email to his supporters, Sanders said his delegates – numbering around 1,900 – are not wealthy and do not have enough money to travel from across the country and stay in expensive Philadelphia for about a week.

This, he said, would cost around $4,000 per delegate.

As such he sought a contribution of $2.70 from his supporters.

"You'd be shocked at how expensive it is to attend the Democratic convention. It can cost more than $4,000 per delegate!" wrote his campaign manager Jeff Weaver.

"Hotels are booked months in advance, and then resold at higher prices. Lobbyists throw all sorts of fancy parties. It's easy for the political establishment to navigate this and know whom to call to find the right way in. That, or they're wealthy enough to pay for themselves," he said.

"Our political revolution is not made up of people like that. Our folks need help to get to the convention and stay there," Weaver said.

Despite having lost the race to Hillary Clinton, Sanders has not withdrawn from the Democratic Party's presidential process.