After a near-wipeout for his party in the general election, Richmond's new Liberal Democrat leader makes no secret of his ambitions.

Councillor Gareth Roberts, who represents Hampton ward, replaces Councillor Stephen Knight as leader of the opposition after he stepped down earlier this month to focus on his Greater London Authority (GLA) role.

He was appointed leader at the group's AGM on Monday evening and said he believes the borough is in "desperate need of some new thinking".

Coun Roberts said: "We want to take the council in 2018 and I believe that we can.

"There is a growing frustration with the decisions taken by the Tories and we need to show ourselves as the credible alternative.

"There is a desperate need for some new thinking and a lot of enthusiasm for an alternative."

After defeating his only rival for the post Councillor Jonathan Cardy, representing Fulwell and Hampton Hill, Coun Roberts stands down as opposition spokesman for education.

Councillor Penelope Frost has been promoted to the role, while moving culture spokesman Councillor Alexander Ehmann to transport spokesman is the only other re-shuffle in his shadow cabinet.

With the leadership issue now resolved, Coun Roberts said his first priority was the GLA elections next May and re-connecting with voters in Richmond.

He said: "We need to concentrate very much on the London elections coming up next year.

"We will continue holding the Tories to account on what is becoming a rather abysmal record in Richmond.

"There have been issues such as schools places, the Gloriana and the takeover from Wandsworth is coming down the lane with, from what I can see, no democratic mandate from the electorate.

"The Lib Dems have to start re-connecting with people in Richmond."

Even before the Lib Dems were reduced to eight MPs nationally, his party suffered huge losses at last year's local elections.

Big names including former leader of Richmond Council Sir David Williams and Brian Miller fell as the party was reduced to just 15 seats on the council.

Coun Roberts said: "There were some grumbles regarding the coalition and we didn't come out of that very well, which I thought was a bit unfair.

"But in 2014, we did very well and the Tories think the general election was an endorsement of them locally but it wasn't, it was the fear campaign run locally that won it.

"Vince Cable was an excellent MP and we owe him a huge debt of thanks.

"He is still involved but now he isn't there, the figurehead of opposition in Richmond will have to start being the leader of the local Lib Dem group."

And with Councillor Tania Mathias elected as the new MP for Twickenham, Coun Roberts is leading calls for her to step down as a Hampton Wick councillor.

He said: "I think there should be a by-election now but my bet is they will keep in until 2016 with the London elections and push it through then.

"That is what they did when the chap went off to Barbados last time, they didn't call one and they waited until the most advantageous time for them, claiming it is all about saving money."

Speaking about what he will do differently from the outgoing Coun Knight, who remains as a councillor for Teddington, he said he wanted to adopt a "team approach".

He added: "Stephen was very good and very powerful - he led very much from the front and I would like to see more of a team approach.

"I'm not suggesting his approach was all about the leader but it is time to start moving forward as a comprehensive alternative to the Conservatives."