Tens of thousands of people in the UK pay fees each year to be a member of a political party.

As party conference season kicks off this September, we look at how much each party costs to be a member of and quizzed the public to see who they think charges the most.

Why do people become members of a party?

Primarily, they join for ideological reasons, according to the three-year Party Members Project led by Professor Tim Bale, politics professor at Queen Mary University.

But people also join for a sense of belonging. For some, it is down to career ambitions.

What do you get for being a member?

Paying to be a member means you can vote for the party leader, and many take part in on-the-ground activism as part of the local party’s social network.

Members also take part in campaigning, although only a small proportion do, the Party Members Project found.

Membership subs provide key financial support for the party, despite most remaining quite low to attract as many people as possible.

Joining up also means you can be a candidate for your party, to try to become a councillor or an MP.

Parties with large, active memberships are often more successful at attracting donations from supporters and party members – after they become paid-up members.

On his research into who joins a political party and why, Professor Bale said: “What the research found was that members of political parties in Britain are demographically unrepresentative.

“That is to say, they’re more middle-class, more middle-aged than the electorate as a whole.

“They tend to come from the southern half of the country, and they tend overwhelmingly to be white rather than from ethnic minority backgrounds.

“We also found that most members aren’t that active. 30-40% of political party members do absolutely nothing for their party other than pay their subscriptions.”

How much does each party charge?

Many of the parties run on a “pay what you want” basis, however, they point people towards the average cost. So, most people pay that amount but some pay much more and some much less.

All the parties have concessionary fees for those who may not be able to afford the general sub.

This differs between parties but is generally lower for students and young people, and some parties have low fees for those on benefits, low earners or people in the armed forces.

What does the general public think?

We asked members of the public how much they think it costs to be a member of a political party and which party charges the most.

The majority of people assumed the Conservative Party is the most expensive, but some guessed Labour correctly.

Most people thought being a member was much more pricey than it is.

Hettie said she thought it would be £10,000 a year to be a member and thought the Conservatives would have the highest fees “because they’ll have the most expensive dinners”.

Rebecca said she thought it would be at least £450 a year to be a party member due to “membership fees, clubhouse fees, probably some socials they have to attend and political contributions”.

On who is the most expensive, she said: “Probably Labour because they need the money to fund all their policies, and they’re probably pushing that whole ‘give us money so we can help others’.

“They probably have the highest fees because people probably feel like they have to give more.”

Jay guessed it costs between £10 and £30 a year to be a member and thought the Liberal Democrats would have the highest fees.

On learning Labour is the most expensive, he said: “No wonder their membership is plummeting.”

Ollie said he did not realise individuals could be a member of a political party as he thought investors “paid up”.

He thought it would be about £100 a year, as did his partner Lauren, who said she would pay that if she “really felt a part of it, felt heard and felt our values were the same”.

Sky News will be covering all the party conferences, starting with Reform from 5 September, Trades Union Congress (TUC) from 7 September, the Liberal Democrats from 20 September, Labour from 27 September, the Green Party from 3 October, and the Conservatives from 5 October.