Biggest and most bizarre party donation? Ms Joan Edwards leaves £520,000 to 'whichever Government is in office'

Directions in will appear to have failed to take into account the Coalition’s formation in 2010

A bequest of £520,000 from a mystery woman left lawyers and Electoral Commission officials scratching their heads.

In her will, Joan Edwards specified that the cash should be given to "whichever Government is in office...to use as they may think fit," according to the Daily Mail, which claims to have seen the document.

In most years it would have been easy to comply with her unconventional wish, but her directions appear to have failed to take into account the Coalition’s formation in May 2010.

In the end the money was divided between the Conservatives and Liberal Democrats depending on the proportion of ministers drawn from their ranks and their number of MPs.

That resulted in her lawyers allocating £420,576 to the Tories and £99,423 to the Liberal Democrats. In both cases, it was the largest single donation the party received in the second quarter of 2013.

The move was decided after Ms Edwards’ solicitors consulted the Treasury solicitors and the Attorney General’s office.

A Tory spokesman said: “It was out of the blue. We weren’t expecting it.”