Opik was joined at his campaign launch by fiancee Lloyd

The party spokesman on Wales, Northern Ireland and young people, Mr Opik announced his candidature flanked by fiancee, weather presenter Sian Lloyd.

Mr Hughes meanwhile says he has consulted colleagues and will announce his intentions on Friday.

The post is currently taken by Lord Dholakia, who retires later this year.

Bright forecast?

The party president is essentially a figurehead who represents the Lib Dems at a range of official functions.

But he or she also chairs events like the meetings of the policy committee of the federal party and is charged with bringing together people from different parts of the party, whether they be peers, MPs, councillors or ordinary members.

It would give Mr Hughes the chance to return to a top party post in the wake of his defeat in the mayoral election. He was previously home affairs spokesman and remains spokesman for London.

There is no competition between me and Charles Kennedy Lembit Opik Lib Dem frontbencher

Mr Opik launched his campaign to become Liberal Democrat president by promising to motivate his party.

The 39-year-old Montgomeryshire MP said he wanted to consult closely with the grassroots.

Joining her fiancee at his official launch at Westminster Ms Lloyd forecast "sunny days ahead". The result of the ballot will be known on 1 September.

Higher ambitions?

The party presidency was currently held by Lib Dem leader Charles Kennedy.

But Mr Opik said: "There is no competition between me and Charles. There can't be. My job is to serve Charles.

Hughes' campaign efforts only won third place

"I see the leader of the party as the captain of the ship. He sets the direction.

"The president is the chief engineer who makes sure that the direction set by the leader of the party is achieved."

Mr Opik has raised his public profile through appearances on shows like BBC 2's Have I Got News For You, as well as his warnings of the need to protect the Earth against asteroids.

Nominations close on 30 June and if there is a contest there will be an all-member ballot of the party.

Mr Hughes said on Thursday: "I have finished consulting colleagues and I'll make my announcement tomorrow."