Sir Menzies Campbell has tonight resigned as leader of the Liberal Democrat party.In a statement at 6.30pm this evening, party president Simon Hughes said: “Menzies Campbell has this evening submitted his resignation as leader of the Liberal Democrats with immediate effect.

Sir Menzies Campbell has tonight resigned as leader of the Liberal Democrat party.

In a statement at 6.30pm this evening, party president Simon Hughes said: “Menzies Campbell has this evening submitted his resignation as leader of the Liberal Democrats with immediate effect.

“For the last two years Menzies has given huge purpose and stability to our party.

“He has made very successful preparations for the general election when it comes.”

Mr Hughes played down rumours that Sir Menzies had been forced out of office, saying:

“Throughout all his political life Menzies has taken his decisions and this decision is one of them.

“Every Liberal Democrat and many other people owe him a huge debt of gratitude.”

Deputy leader Vince Cable takes over leadership of the party with immediate effect, until a new permanent leader is announced.

Sir Menzies, 66, took over as leader of the party following the resignation of Charles Kennedy in January 2006.

He has recently faced criticism over his ability to communicate Liberal Democrat policies to the general public, in the face of headline-grabbing announcements from Labour and the Conservatives.

In Suffolk, Liberal Democrats had praise for the achievements of Sir Menzies during his term in office.

Leader of Suffolk County Council Liberal Democrats Kathy Pollard said: “Ming has done a fantastic job in his time as leader, especially in preparing the party for the general election that nearly was.

“The job of leadership is always difficult and I think Ming brought substance to politics at a time when the other two leaders seemed more interested in spin.

“Now is the time for the party to get behind the new leader and prepare to offer an alternative to the other two parties; especially on climate change, long-term care for older people, council tax reform and the catastrophe in Iraq.

“We hope his whole experience and wisdom continue to play a central role in the party.”

Sir Menzies made one of his last public appearances as leader of the party when he spoke at their eastern regional conference in Mildenhall on Saturday .

Kathy Pollard said: “He was very warmly received - he spoke about the shortcomings of the other two parties and the way ahead for the Liberal Democrats.

“He said he was prepared to go on and fight the next general election but events have obviously overtaken him.”

She also said she felt bad that Sir Menzies age had often been held against him in the political arena, saying: “I think there was a lot of ageism against him, which is very sad. It is only in recent years that parties have fielded younger candidates as leaders.

“I feel extremely sorry for Ming and hope he will continue to play a central role in the party.

“His experience is unparalleled.”