JUST before the yellow peril gathered by the Dorset seaside, Paddy Ashdown bemoaned how the Liberal Democrats had not had “one big, dangerous idea” since the Coalition years and that his beloved party now faced an existential challenge.

Of course, the Lib Dems do have one such idea: a “vote to exit Brexit”. But, as yet, it does not seem to have grabbed the public imagination in any significant way; time will tell.

Indeed, privately, a number of MPs seem themselves to be rather lukewarm on the idea, not seemingly convinced it is a vote winner; not yet anyway.

Ahead of the snap General Election when Tim Farron declared, rather foolishly, that his aim was not to get his policies realised but to become Leader of the Opposition, the party leadership had high expectations of the electorate.

That as Labour lurched to the Left under Che Corbyn and the Tories veered Right under Maggie May, the electoral sea would open up in the centre and the Lib Dems would skip to the Promised Land. The reality was the waves did not part and Mr Farron and his party managed to swim and gurgle their way to the shore with just four extra MPs.

Tiger Tim has now departed to be replaced by Uncle Vince, declaring how he has more ambition and wants to be Britain’s next Prime Minister. Remember, the Lib Dems only have 12 MPs.

Party lieutenants are hoping that voters will once again warm to the professorial Cassandra, who back in 2007 was warning about the dangers of rising debt and the catastrophe to come. They are still hoping the Red Sea effect will happen and the Lib Dems will scoop up lots of centre ground support.

While the Lib Dems’ campaign for an “exit to Brexit” poll is front and centre, the party is keen not to be seen as “just Ukip in reverse” and is addressing the concern Lord Ashdown raised about producing radical ideas.

After Sir Vince in his keynote speech insisted “I told you so” on the Iraq war, the economic crash and now Brexit and cracked a few jokes at Labour and the Tories’ expense, he focused in on the youth vote.

The party leader this week told conference about how his party would need to be “brave” in addressing the issue of housing and generational inequality.

In his keynote speech he mooted a combination of hitting foreign oligarchs with “fierce tax penalties” to bring down property prices, most notably in London and other big cities, and doubling the annual housing supply to buy and rent.

As well as looking at the fraught issue of tuition fees and student debt, the Lib Dem leader insisted his party would always be the “voice and champion” of young people.

But the party needs to beware. If it does indeed place its political emphasis on helping the non-property-owning Generation Rent, it could alienate the property-owning Grey Vote. Politics is never easy.