Water companies should immediately be brought into public ownership with shareholders getting no compensation, the Green Party’s deputy leader will say later.
Rachel Millward will argue the Prime Minister is “making a mistake by delaying any action” against firms such as Thames Water.
In his first Labour Party conference speech earlier this week, Mr Burnham said new legislation would repeal “Margaret Thatcher’s ideological ban on public ownership of water companies”.
He said it would start a decade-long process to strengthen public control, with mayors getting “new powers to hold water companies to account, with tougher consequences for those which repeatedly fail”.
Ms Millward will say in her speech: “Burnham’s 10-year plan of gentle threats and vague notions of control is not enough.
“Thames Water and South East have failed. They have not fulfilled their statutory duty.
“Right here in Sussex, we find ourselves for days on end having to drive to pick up bottled water because nothing is coming out of our taps. Not a single major reservoir has been built since the beginning of privatisation, despite councils giving planning permission.
“So stop this talk of 10-year plans and putting them on notice. We need public ownership now, and we have all the tools we need to make it happen.
“Forget compensation for shareholders and creditors, these are insolvent companies. It’s time to take them back.”
Elsewhere on Saturday, the Greens are set to announce a new policy to provide a guaranteed job for every 18 to 24-year-old.
The jobs will last up to two years, and will start within four months of people leaving education or training, deputy leader Mothin Ali will announce.
He will tell the Greens’ conference: “Working class kids should be able to dream.
“But more than dreams, they should have a genuine chance of making those dreams into reality.
“Threatening young people with cuts to universal credit if they do not accept short-term work placements is not a youth strategy.
“Ignoring the two-way link between mental health and unemployment is not a choice.
“Failing to take targeted action to connect our young people with jobs of the future is not OK.”