Tony Blair is considering plans to make a significant donation to the Labour party to help Ed Miliband fight next year's general election. On the eve of a likely decision by the Unite union to make a substantial cut in its contributions to Labour, the New Statesman reported that the former prime minister is considering making a "large donation".

The timing of Blair's plans will fuel speculation that he is keen to reward Miliband for his bravery in reforming Labour's links with the trade unions.

Unite, whose general secretary Len McCluskey has said that Miliband's reforms will hand union leaders greater powers by giving them greater control of their political funds, will announce today whether it will cut its donations to Labour by a further £1m.

It is understood that Blair is keen to offer Labour support in the runup to next year's general election by offering a higher donation than the amounts he has given in recent years. It was unclear whether it would match the £76,000 Blair donated in staff and resources during the 2010 election.

Friends were keen to dismiss rumours that Blair is now worth £75m. They were also keen to point out that he has major financial commitments supporting charities and companies that employ nearly 200 people. He has made charitable donations of £10m since 2007. That includes £4m to the Royal British Legion.

Lord Levy, Blair's former fundraiser for Labour, said earlier this week that Miliband should not be afraid of accepting private funds for "something you believe in". Levy told The Times: "Does Labour want to do it? I don't think they've got any option. Is it something Ed Miliband is in love with? No, I don't think it is. Will he have to do it? Yes, I think he will."

The former prime minister, who was highly sceptical of Ed Miliband's leadership credentials in 2010, praised the Labour leader for going further than he dared in reforming the party's links with the trade unions. Blair said: "Ed has shown real courage and leadership on this issue. It is a long overdue reform...[and] was something I should have done myself. It puts individual people in touch with the party and is a great way of showing how Labour can reconnect with the people of Britain."