During a debate on the Government's third sector review in the Commons last week, shadow charities minister Greg Clark asked Miliband if he believed that a charity "should be able to devote 100 per cent of its resources to campaigning politically". Miliband said: "No, that is not my view."
Clark seized on Miliband's words as evidence that the Government had been swayed by the Conservative Party's arguments on the issue and changed its stance.
In the third sector review, published in July, the Government said: "Provided that the ultimate purpose remains demonstrably a charitable one, the Government can see no objection, legal or other, to a charity pursuing that purpose wholly or mainly through political activities."
But a spokeswoman for Miliband denied the Government had ever been in favour of allowing charities to use all their resources for political campaigning.
"We support the Charity Commission's guidance from April 2007 that says, although charities can dedicate all of their resources to political campaigning for a period of time, they cannot do this in perpetuity," she said. "We think it would be wrong to change the law on this matter.
"We are waiting to see what the commission's new guidance says next month and whether this clarifies the situation. But we are not persuaded that there is a case for changing the law."
The Conservative Party has consistently and vehemently voiced its opposition to the coalition's proposals. The coalition is seeking a meeting with Clark to discuss his concerns.
"We would welcome the opportunity to put our arguments to Greg Clark in person," said Ian Leggett, director of human rights and environmental charity People & Planet and a member of the coalition.
"It has been claimed that we want charities to be able to have political objects, but we have never proposed that and we are totally against the idea of charities being in any way party political.
"This is about giving trustees the choice of dedicating all their resources to influencing public policy."
Clark said he would be happy to meet the coalition. "Although they say they are not proposing that charities should have political objects, the outcome of what they are proposing means the difference would be negligible," he added.