At first glance, it is hard to see what beer, wood panels, tennis, ship building and the Bahamas have in common.

But one thing unites them: they are all issues and subjects that Kent MPs have an interest in through their membership of all-party parliamentary groups.

The role of these informal groups has been thrust into the spotlight in the wake of fresh sleaze allegations, which have led to questions about their role and whether there are too many. This week, the Prime Minister said they needed to be looked at.

An analysis by the KM Group reveals the county's MPs together sit on more than 140 such cross-party groups across a range of topics, from the interests of Africa's Great Lakes through to dementia, Channel 4, greyhound racing and women in sport.

One MP - the Thanet South MP Laura Sandys - is recorded as belonging to 37 while others belong to only a handful.

Far from considering them talking shops or excuses for trips abroad, most of the county's MPs believe they do an important job, helping shape government policy and providing a forum for constituency interests.

Dartford MP Gareth Johnson points to a report highlighting the postcode lottery of infertility treatment across the country, published by the group on infertility he chaired.

After its publication, a number of primary care trusts who limited access to such treatment changed their policy and made it more widely available.

Mr Johnson said: "I have no doubt that there are babies alive who wouldn't have been but for our report. It forced trusts to address the issue."

But even he acknowledges the proliferation of such groups probably needs to be checked.

"In general, they are a good thing. But the criticism that there are too many is probably valid."

Several MPs are key figures in committees, acting either as chairmen, vice chairs or secretaries.

Chatham and Aylesford MP Tracey Crouch, is a member of three devoted to sport, acting as vice chairman of a group on women's sport and fitness.

She argues they provide a valuable channel for MPs to raise issues with ministers. She points to the dementia group, which has made three reports and is about to issue a fourth, as a good example.

"They offer a real opportunity to feed into government policy. They are cross-party so it gives us the opportunity to look at issues in a more considered way. And as a group, we often have ministers come along to talk to us."

She is uneasy about the idea that there should be fewer and a cull is needed.

"It would suggest some are more valuable than others. There are a lot of policy issues out there."

Canterbury MP Julian Brazier, who was inadvertently caught up in the latest allegations involving claims made against MP Patrick Mercer, is adamant the groups perform a valuable service.

"We absolutely need them. It is very important that colleagues work together - if there is one thing that constituents complain to me about it is that as politicians, we do not work together enough."

He does not see any case for tighter regulation. "The rules around registration are fine - you have to register any interests you have."

He cites his role in the All Party Group on Adventure and Recreation in Society, which led to the Compensation Act 2006 - countering the "compensation culture" restricting opportunities for young people to take part in potentially risky activities.

But one MP sounded a note of caution.

The Rochester and Strood MP Mark Reckless said he selected carefully as they were only one aspect of what an MP did: "They do make a valuable contribution but that can be more
limited than select committees, for example.

"There are reputational

issues for MPs, particularly with foreign countries."

Additional reporting by Matt Leclere

It seems there are few subjects that do not come under the gaze of all party groups, judging by the official register.

And Kent MPs are members of some of the arguably more "special interest" groups.

Canterbury MP Julian Brazier is listed as a member of the all-party greyhound group - devoted to "raise parliamentary awareness of issues relating to the greyhound industry and to promote the sport."

Adam Holloway (Gravesham) is among members of the Wood Panel Industry group - MPs who are "concerned about the impact of unrestrained growth in co-fired power generation on the wood panel industry."

Gillingham MP Rehman Chishti is among a small number of MPs on the tennis all-party group - which is described on the Parliament website as "for MPs and Peers to be able to play tennis matches together and compete with various outside tennis teams."

Thanet South MP Laura Sandys sits on the group devoted to the African Great Lakes Region - devoted to ensuring the Great Lakes region "is on

the political agenda of the government."