The Liberal Democrats gather for their annual conference in Bournemouth on Saturday with a real spring in their step.

The venue may be familiar - it's their third visit to the south coast in the past five years - but in every other respect things look rather different.

The resurgent party has a new leader, quite a few more MPs, growing political momentum and a new-found hope of playing a pivotal role in the unfolding Brexit drama.

So what can we expect over the four days?

1) Jo Swinson's big debut

Image copyright Reuters Image caption Jo Swinson will be in the spotlight on Tuesday

Whatever else happens, the event will ultimately be defined - in terms of press coverage anyway - by Jo Swinson's leader's speech on Tuesday.

Her predecessors - Tim Farron and Vince Cable - struggled to achieve a real breakthrough beyond the conference hall, as the party languished in the doldrums.

This is unlikely to be the case this time, when Ms Swinson takes the stage at about 14.30 BST.

The 39-year old is a fresh face - despite being a relative veteran in Westminster. She is the party's first female leader, as well as its youngest.

There will be a lot of interest beyond Lib Dem circles as to how she performs, the degree to which she reaches out to other parties on Brexit and her positioning on key issues.

After all, many people think a general election is inevitable before the end of the year - an election which could offer the party the best chance of progress in nearly a decade.

2) More defections?

Image copyright PA Media Image caption Will there be a surprise defection?

Following the 2015 election, the jibe that you could fit all the Lib Dem MPs into the back of a taxi was heard for the first time in a generation.

After five years of governing in coalition with the Conservatives, the party had been reduced to a rump of eight MPs in Parliament.

But now things are moving in the opposite direction, with the party's ranks swelling to 17 (or 18 if you include one MP who has lost the whip).

Since June, two former Labour MPs, one former Conservative and a serving Conservative, Phillip Lee, have joined the party. Mr Lee's defection, which came as Boris Johnson was addressing MPs in Parliament, was particularly dramatic.

Could we see others join them this week? There's a reasonable chance, as parties love to unveil high-profile converts with a flourish in the glare of the TV cameras.

There are more than 20 ex-Conservative MPs sitting as independents in the Commons who are opposed to a no-deal Brexit and, in some cases, opposed to any kind of Brexit.

As it stands, they have been told they cannot represent their old party at the next election. Will some be tempted to throw their lot in with the Lib Dems?

3) Stop Brexit calls

Image copyright EPA Image caption Stop Brexit is set to become the party's election slogan

The party's strong opposition to Brexit - it has supported another referendum for the past two years - has hardened in recent weeks.

Ms Swinson now says that if the Lib Dems win power after the next election - a long shot admittedly - they would revoke Article 50. This would halt the legal process underpinning the UK's departure, and nullify the 2016 Brexit referendum vote.

The leadership will ask party members to endorse this position in a debate on Sunday.

It will also seek a mandate to campaign on a Stop Brexit ticket at the next election and for the party's backing for giving all EU nationals in the UK settled status automatically.

Expect the motion, which states there is "no negotiated deal that could be more beneficial than continued membership", to receive overwhelming backing.

But it will be interesting to see how many dissenting voices there are, perhaps worried about the message it sends to Leave voters.

Among them could be Eastbourne MP Stephen Lloyd, who lost the whip after backing Theresa May's Brexit agreement, and ex-minister Norman Lamb, who is standing down at the next election but who has joined the cross-party "MPs-for-a-deal" group.

4) Hellos and goodbyes

Image copyright PA Media Image caption Chuka Umunna will make his conference debut for his new party

This is a party in transition and this year's event will reflect that.

This is likely to be Vince Cable's last conference as a Lib Dem MP, the former leader having said he won't contest his Twickenham seat at the election.

It will also be Chuka Umunna's first as a Lib Dem. The former Labour politician has been given the plum Monday morning speech slot - second only in prestige to the leader's closing address - and he is likely to command plenty of attention.

There are also speaking slots for Jane Dodds, the newly elected Brecon and Radnorshire MP and Welsh party leader, and Siobhan Benita, the party's London mayoral candidate.

There are likely to be a few tears and quite a few cheers during the party's tribute to its beloved former leader Paddy Ashdown, who died last December.

Expect some big names on the fringe, although it is not clear whether ex-deputy PM and now Facebook exec Nick Clegg - normally one of the week's biggest draws - will be among them.

5) Making policy

Image copyright PA Media Image caption The party will debate a ban on single-use plastic

Unlike other parties, Lib Dem members have a say in policy-making, which makes debates - even on obscure subjects - worth keeping an eye on.

Activists will debate motions calling on the government to pass a law to scrap the "gender price gap" on all consumer items and extend equal marriage to Northern Ireland.

Far-reaching reform of the tax system will also be on the agenda, with a proposal to scrap corporation tax in favour of a new British business tax, while measures to tackle poverty and job insecurity include a 20% minimum wage for workers on zero-hours contracts.

Increased focus on prisoner rehabilitation would see only women convicted of the most serious and violent crimes sent to prison, and an end to custodial sentences for personal drug use. There would also be tax discounts to encourage firms to employ ex-offenders.

On education, the party wants to extend the pupil premium to 16 to 19-year-olds and - on the environment - to ban all non-recyclable single-use plastic within three years.