Sir Menzies was criticised for his performance in the Commons

Earlier this month, Mr Hughes - beaten by Sir Menzies in the party leadership race - said the leader "needed to be judged" at the party conference.

It came after Sir Menzies was criticised over his performance at the weekly Prime Minister's Questions.

He said he had since had a "free and frank" discussion with Mr Hughes.

"Let me put it this way: I think there were other ways of expressing the position other than those that he chose," Sir Menzies told the BBC's Five Live.

"But I am determined that the party which I now have the privilege to lead is going to take advantage of a quite remarkable political opportunity available to us."

Liberal Democrat Scottish leader, Nicol Stephen, praised Mr Campbell's performance as leader.

He told the BBC: "I think he's doing exceedingly well. The party in Scotland is doing fantastically."

'Fair comment'

Tension in the party emerged after Sir Menzies' performances during Prime Minister's Questions came under fire.

Chief of staff Norman Lamb had advised Sir Menzies to "relax and be himself" in the "bear pit" of the Commons.

The party press office also said it was looking at ways to improve Sir Menzies' performance at Prime Minister's Questions, including considering changing the sort of questions Sir Menzies asked.

At the time, Mr Hughes said the party should not be quick to judge its new leader but "take stock" of his progress at the Lib Dem's annual September conference. He said it was "fair comment" to suggest more effort should be put into the leader's performance.

"Ming is fully aware of that," he told GMTV.

"He will now have time to be in Westminster and concentrating, but it's not to be underestimated the work that needed to be done behind the scenes for getting the policies sorted."