It costs nearly £42,000 to become a Tory MP, according to new estimates.
Is becoming an MP too costly for many people?
Research by the Conservative Home website suggests days away from work, setting up home in a constituency can cost even losing candidates £27,235.
The figures are based on a survey of Tory candidates. The prohibitive costs could be a barrier to recruiting people with lower incomes, it suggests.
Tory candidates' chief Bernard Jenkin said help was given to some candidates but the system needed to be improved.
Party officials also suggest that becoming an MP can be expensive for members of all parties.
The estimates are published as the Conservatives add about 100 people to their A-list of elite candidates.
Local associations are being encouraged to pick A-list candidates, at least half of whom are women and 10% are from ethnic minorities.
Conservative Home's research was based on a survey of 17 Tory A-list candidates and 20 other candidates.
It says the cost for winning candidates is £41,550 and the average cost of fighting a seat, including lost income, is £34,392.
The main costs are:
- Basic costs of becoming and staying a candidate, including £250 for assessment boards and extra for other interviews.
- Costs of finding a seat - travelling to selection meetings and recce trips costing about £150; paying for extra training, perhaps £500 a day
- Fighting the seat - Funding accommodation to be a "local" candidate (one candidate spent £20,000 renting a home in their constituency); attending local Tory association events and "buying endless raffle tickets"; travel costs
- Lost income - one person says they lost the chance of promotion because they did not spend enough time in the office, another lost their job completely, and another candidate thought the profits of their own company halved as he gave it less attention.
The report says candidates become "slaves" to Conservative headquarters as they are expected to go to campaign in by-elections in different parts of the country.
One candidate said he was told by his constituency chairman to go to a "must attend" ward meeting.
The train and taxi for his wife cost £80 (his car was being serviced), babysitting cost £20, the event tickets another £10.
He said: "I donated a £20 bottle of House of Commons whisky to the raffle. I spent £25 on rounds of drinks and £5 on raffle tickets.
"There were only 25 Tories at this 'must attend' event, few of them ever did anything for the party. There were no floating voters there.
"We got into bed that night at 1am. I was woken at 8am with a call from my association chairman. There had been complaints from two members that my wife hadn't bought any raffle tickets."
Mr Jenkin, the Conservative vice-chairman responsible for candidates, told BBC News the cost estimates were "conjecture" but were a legitimate worry.
"Historically what we have done in the Conservative Party is to ensure that less well-off candidates are quietly helped," he said.
"I personally think we need to make the process more open and to make sure that we are determined to help people from all backgrounds try to become Conservative candidates."
The new 'elite'
The latest wave of A-list candidates is being chosen amid claims that the Tories are not making enough progress in becoming more representative.
Labour chairman Hazel Blears said the latest people added to the list were "B-list" candidates not thought good enough to fight marginal seats two months ago.
But a Tory spokeswoman said topping up the list had always been planned.
Since the A-list began, 17 constituencies had chosen candidates, she said.
Nine of them chose A-list candidates and women had been selected in six of them.
Overall, 13 of the 40 Conservative candidates chosen for the next election are women, she added.