Energy Secretary Chris Huhne says the coalition will not rush a deal on the size and scope of the Green Investment Bank, which is being set up with at least £1 billion to fund clean energy and low carbon projects.
Mr Huhne told MPs there were “ongoing discussions” between the ministers on the formation of the bank.
Campaigners have warned that the bank must be properly financed in order to help Britain tackle climate change and energy security, amid concerns that Liberal Democrats are at odds with the Treasury on the issue.
At Commons question time, Labour's Ian Murray (Edinburgh S) asked whether the Department for Energy and Climate Change had been “heavily involved” in the bank's development.
“What input have you had in the formation of the bank and can you tell the House if you're in favour of a bank or a fund, or if the Treasury's pushing you towards a fund in order to keep it off their books?” he asked Mr Huhne.
The Energy Secretary replied that there are “ongoing discussions between ministers and I would merely make the point to honourable gentlemen and ladies opposite that it's more important to get this right than to get it wrong and do it quickly”.
"Remember that with the Green Investment Bank, we're looking at an institution that is going to be crucial in supporting the transition to the low carbon economy - not over a two year period, a three year period, but over 40 years,” he said.
Announcements would be made in due course, he said.