Labour would impose a levy on the profits of payday lenders that would be used to double the amount of public funding for low-cost alternatives, such as credit unions.

The levy is intended to raise an additional £13m from the much reviled payday loans industry, and will be seen as another attempt by the Labour leader, Ed Miliband, to take the side of the consumer against "profiteering capitalism".

Miliband will also confirm that Labour would impose a cap on the cost of credit and give councils the power to stop the spread of payday lending shops in town centres.

He will announce the next steps in his cost of living campaign as he also reveals Stella Creasy, the new shadow minister for competition and consumer affairs, will lead Labour's campaign against legal loan sharks.

It comes on the day that the archbishop of Canterbury, Justin Welby, urges Anglicans to help the formation of credit unions in their localities as a way of beating back the payday lenders.

Creasy has been campaigning energetically on the issue for more than two years, and has played a part in forcing the Office of Fair Trading to demand reforms from the industry. Her transfer from shadow home affairs team to the shadow business team gives her formal party responsibility for the issue for the first time.

Miliband will say the levy will be in addition to the levies the payday industry is due in April to hand to the new Financial Conduct Authority (FCA) to help fund services such as debt advice.

He will claim the payday loans industry is making very high profits, and this levy need not lead to an increase in the cost of loans.

Labour says it will consult on the level of rate of the proposed cap on the cost of credit and details of its addition to the levy, but the intention is to double the income due to be received from existing levies, bringing £26m in total from the industry.

David Cameron said he was open to the idea of a cap on payday lenders at prime minister's questions on Wednesday, saying: "We continue to look at the issue of a cap and I don't think we should rule that out."

But he added: "We do have to bear in mind what has been found out in other countries and through our own searches about whether a cap would prove effective."

Earlier in the year the coalition allowed amendments to give powers for the FCA to introduce a cap.

But Labour claims the FCA is reluctant to use these powers, and the party has criticised the government for not doing more to speed up the decision.

Miliband has also promised to change planning law to make it easier for councils to prevent payday lenders filling a high street where banks close. Labour suggests that councils should be given powers to assert that a change from a bank to payday lender represents a change of planning use and can therefore be blocked by the council.

Miliband is on Thursday expected to say: "The market in payday lending has doubled in just four years. Almost a third of payday loans taken out in Britain at the moment are to cover the cost of people's gas and electricity bills. For too many people the end of the month is their own personal credit crunch.

"It is right that companies that benefit from people's financial plight accept their responsibilities."

Creasey will say: "Across the country Sharkstoppers and Debtbusters campaigners are working to address the damage payday lending debt is doing to the finances of millions of families.

"Whether helping to increase the capital that credit unions have to enable them to lend more, kicking these companies out of football grounds and shopping centres or supporting debt advice to those caught in the spiral of debt by the practices of these firms these are the people that are dealing firsthand with this government's failure to learn from other countries in capping the cost of credit."

Welby said the aim was to double the number of credit unions over five years, adding the church could do more to help the formation of credit unions themselves, including through the formation of a Church Mutual Credit Union.

In a message on Thursday he writes: "Our faith in Christ calls us to love the poor and vulnerable with our actions. That is why churches must be actively involved in supporting the development of real lending alternatives such as credit unions. That is not an optional activity, but a fundamental part of our witness and service to God's people."