Nick Clegg's opposition to childcare reforms is part of an effort to fight off internal efforts to oust him as Liberal Democrat leader, Education Secretary Michael Gove said.
In an extraordinary attack on his coalition Cabinet colleague, Mr Gove said the Deputy Prime Minister "has to show a bit of leg" amid reports of efforts to undermine his position.
Mr Clegg has signalled that he does not support loosening staff-to-child ratios in nurseries - part of a package of nursery reforms being championed by Tory education minister Liz Truss which emerged after months of wrangling between the coalition parties.
Ms Truss has argued that the changes would lower childcare costs and allow professionals in the sector to be paid higher salaries. But Mr Clegg pointed to concerns expressed by many groups in a consultation and questioned claims the policy would result in cheaper childcare costs for parents.
Mr Gove told BBC1's Andrew Marr Show that the reforms were "absolutely right" but that he was prepared to look at "an adjustment here or there" to meet concerns. Asked about Mr Clegg's position, he said: "I don't think we can understand Nick Clegg's position without also appreciating the position he is in because of internal Lib Dem politics.
"There is a campaign being led by Matthew Oakeshott, this Liberal Democrat in the Lords, to try to destabilise Nick Clegg because Matthew Oakeshott wants Vince Cable to succeed him. Nick, understandably, needs to show Lib Dems that he is fighting hard.
"I understand. That's one of the things that happen in coalition. We have had discussions with Nick in the past where we haven't always had the same starting position but in the end, because he is a reasonable guy, we have managed to find an appropriate synthesis. I think he would appreciate that the logic of what Liz wants to achieve is formidable. Of course, if there needs to be an adjustment here or there in order to make sure that it works for everyone. We will consider that."
He went on: "Lord Oakeshott is on manoeuvres, he is trying to promote Vince. It is understandable that within the Lib Dems these things go on. Nick has to show a bit of leg, as it were, on these issues.
"But we have seen these issues arise in the past and we have managed to resolve them in the national interest and I think it's only appropriate that we have an opportunity over the next week or two to ensure that the logic behind Liz's position and any concerns that have been raised can be reconciled so that children get the care and attention they need in order to arrive at school ready to learn."
Lord Oakeshott, a close ally of Mr Cable who in the past has suggested the party should consider ditching Mr Clegg as leader, insisted there was "no plot". "Gove tries diversion from Cons Europe split with old news," he posted on Twitter. "I prefer Cable to Clegg, shock! But there's no plot - members decide who leads us."