By Mark Davies BBC News Online political reporter

And next to that is a sub-heading: "Loony Left policies of Lib Dems' boozy chief".

You might have thought the two-page spread in the Sun would outrage the Liberal Democrats.

The sort of treatment metered out to Neil Kinnock - still a running sore in Labour circles - is now, it seems, being applied to Mr Kennedy.

Has Kennedy stormed the two party system?

The party leader himself was sanguine about it when asked for his views on Tuesday, saying it showed the party could not be ignored. Others will be angry. But most will also recognise that there is some good news here: the Lib Dems are being noticed.

And in the fringe meetings and bars in Brighton this week, the murmur among the faithful - buoyed by the Brent East triumph - is an optimistic "it's all up for grabs now".

The party takes heart from polls suggesting that what might be happening in the UK is the creation of a new political order where the old right and left labels no longer apply.

The Lib Dems, it is argued, represent a genuine choice for those stepping outside those traditional tags to look for a party aligned with their way of thinking.

The party's president, Lord Dholakia told the conference on Tuesday that the political landscape "is changing and changing fast. I am happy to say the grass is greener on our side".

And at a fringe meeting this week, the MEP Nick Clegg made an important point which should resonate with both Labour and the Tories: voters, he argued, are for the first time disillusioned with both the main parties.

Opportunists?

The surge of support for Labour during the woes of the last Tory government has evaporated, he suggested, with floating voters now looking to the Lib Dems.

At another fringe meeting, home affairs spokesman Simon Hughes talked of a "coalition of the willing" - those who step outside traditional party boundaries.

The question now, he suggested, was whether one is "radical or conservative". At the same meeting, former cabinet minister Baroness Williams argued that many of the issues at the forefront of political debate at present transcend the left and right tags.

The main parties will, of course, brush off such suggestions by saying the Lib Dems are simply opportunists who wear whatever colours suit depending on their surroundings: left of Labour in Brent East, closer to the Tories in leafy middle England.

Indeed, Tory leader Iain Duncan Smith suggested that the Lib Dems had blown it in Brent East by casting themselves as more left than Labour - a charge laughed off by Mr Kennedy.

Polls this week, however, suggested that to some degree voters do indeed see the Lib Dems in a different light depending on where they stand in the political spectrum.

Election challenge

The Populus poll in The Times suggested that the average voter has views just to the right of the political centre, with him or her seeing Labour as just to the left and the Lib Dems further to the left. The Tories were seen to be firmly on the right.

The concern for Labour should be that many of its own supporters feel the party is further away from their views than are the Lib Dems. For the Tories it is that their supporters, according to the poll, see Charles Kennedy's party as not as left as Labour and a possible alternative to Iain Duncan Smith's party.

The challenge for him, though, is to prove to voters then when it comes to the main event - a general election - the Liberal Democrats really are a viable alternative to the big two Charles Kennedy Lib Dem leader

That seems to suggest that while the main parties can roll out the "opportunist" tag, for the people that matter - the voters - the Lib Dems do present a worthwhile alternative to both the Tories and Labour.

It's not all good news though: according to the poll, many voters still see the Lib Dems as a "protest party" and are doubtful about some of their policies.

This week in Brighton the party will seek to change that view and build on the success of Brent East.

Mr Kennedy will shrug off newspaper attacks, and has already said that any suggestion that voters are obsessed with whether a party is left or right is "claptrap".

He may have a point. The challenge for him, though, is to prove to voters then when it comes to the main event - a general election - the Liberal Democrats really are a viable alternative to the big two.