All that money begs an obvious question: Why are organisations that are set up to help the poor and disadvantaged so rich?

The answer according to the charities is that they are saving for a rainy day.

Although the wealth of the richest charities is growing faster than either their income or the amount they spend, there are currently no strict guidelines in place as to how much they can hold in reserve.

Are stockpiled funds allowed?

According to the Charity Commission, reserves are made up of "income funds freely available for spending on any aspect of the charity's work."

Assets include the value of it's buildings and property, endowments which must be invested to produce an income, and legacies or gifts given on condition they are spent in a specific way.

While it does not currently stipulate a level for reserves, the Charity Commission's guidelines state: "If it is done without justification, the holding of income in reserve may amount to a breach of trust."

"We say it is up to each charity to work out what level of reserves it needs," a spokesperson for the Commission said.

"It should be able to justify its and should explain it in the charity's annual report. We monitor charities' reserves annually and will take up any case where reserves look unjustifiably high."

Guarding against catastrophe

Like many others, The Royal Society for the Protection of Animals (RSPCA) justifies its reserves on the grounds that they are a safeguard against fluctuations in income.

It says reserves guarantee that it could continue to continue its activities in the event of "hard times". The stockpile stems from its experience 20 years ago when a lack of donations nearly caused the society to go bust.

"In the event of a catastrophe we wanted to ensure that out funds would last at least 18 months while we got our feet back on the ground," Head of Fundraising Anthony Baumann said.

But although it has a policy that it will hold a minimum of £45m in reserve, the RSPCA currently has reserves in the order of £150m.

"At the moment are reserves are well in excess of our policy but those funds are in fact ear-marked for specific projects which are awaiting planning consent," Mr Baumann said.

Charting a successful future

RNLI: almost absolvent in the 70's

The Royal National Lifeboat Association (RNLI) has more than £250m invested and a further £150m in assets making it the 13th richest charity based on funds.

The charity also fell on hard times 20 years ago and holds reserves as a safeguard against a similar situation in future.

"We were down to virtually no reserves and we were making plans to close lifeboat stations," the charity's deputy director, Ray Kipling said.

"In order to provide reasonable security for the future, the Trustees have set aside a long-term reserve at a level judged to be capable of sustaining the RNLI through a future period of financial decline."

The Guide Dogs for the Blind Association, which holds £200 million in investments and assets, is currently looking at its reserves within a wider review of its finances.

"The investments that we had made over the years with legacy income performed very well on the stock market and our reserves have grown greatly in the last five years," the charity's chief executive, Geraldine Peacock said.

"So for the last 15 months we have been taking a long hard look at the organisation and its future to see what we could do with this improved income to improve the range of services that we could offer," she said.

Many big charities are going into fundraising overdrive in the lead up to the millennium.

Although low inflation and economic strength in the UK has benefited charities in recent years, there is growing concern about future recession.