Organisers of a poll to designate a wild flower for every county in Britain believe the contest has been rigged by Sussex plant-lovers.

Sussex was one of 20 places where the bluebell came out on top in the survey conducted by conservation charity Plantlife.

But co-ordinators became suspicious about the high number of votes in parts of the South and have decided to run the contest again.

Jane Smart, executive director of Plantlife, said: "We definitely detected clusters of voting in Sussex for the bluebell and think there were numerous local campaigns to drum up extra votes for the flower."

The bluebell has now been removed from the list of options and people in Sussex now have to choose between the birdsfoot trefoil or the round-headed rampion.

Both are downland species, although Sussex faces competition from Essex for the birdsfoot trefoil.

The nominations have drawn a mixed response from flower experts.

Lee Bishop, who chairs the Wivelsfield Flower Club, said: "The birdsfoot trefoil grows on downland but is quite an insignificant flower.

"I would rather see a scabious, which is very pretty and grows along the downs to Plumpton."

David Streeter, a reader in British vegetation and flora at the University of Sussex, said: "The round-headed rampion is already associated with Sussex as the symbol for the Society of Sussex Downsmen.

"There is more of it in Sussex than anywhere else.

"It has a head of blue flowers, stands up to 18 inches high and flowers in late summer, from July through to September. It is very much a special Sussex plant."

All counties in England, Scotland, Wales and Northern Ireland have been given two shortlisted flowers.

Residents are able to vote online for their chosen species at www.plantlife.org.uk