The message was part of an email, seen by Accountancy Age and sent to the trustees of 8,000 UK charities by the Charity Commission.

Simon Gillespie, director of operations at the commission, said that accountants and auditors needed to give charities the help they required, although he stressed that 'ensuring accounts are filed on time is the responsibility of trustees'.

The email forms part of the commission's 'Accounts aren't optional' campaign, aimed at reducing the number of organisations that submit late. Last year this included more than a third of the 62,176 UK charities, which must file accounts with the commission. This prompted the House of Commons public accounts committee chairman Edward Leigh to accuse the offending organisations of 'treating the commission with contempt'.

Charities also face the threat of an investigation, although Gillespie stressed the committee 'did not want to use its formal powers'. These include the ability to suspend trustees and employees, freeze bank accounts, prohibit further fund-raising and appoint a receiver manager to run the charity instead of the trustees.

As part of the watchdog's campaign, the details of defaulting charities have been published on its website. Under UK law, charities that have a gross income in excess of £10,000 are under a statutory obligation to file annual reports and accounts to the commission within 10 months of the end of their financial year.