The seven - contesting key borough watds - planning to stand on an 'Independent Save Priory Park' ticket so voters would know exactly what they stood for.
That, apparently, is not legal!
And it's all because some crafty politicians stood as Literal Democrats to spoil the 1997 west country general election and hand victory to the Tories instead of the Lib Dems.
Now only registered political parties can be listed on ballot papers.
So while the campaigners can push the park cause in their own election literature - all that voters will see when they get to the polling booth is the name and the description 'Independent'.
Peter Walker, who is contesting Prittlewell ward as Independent Save Priory Park, is disappointed.
"When we checked with the council we could appear on the ballot paper as Priory Park campaigners. Then we were told we couldn't," he said.
"We will canvass strongly on the point - so that voters will be in no doubt what we are about when they come to mark that 'x'", he added.
Andrew Wallace, deputy returning officer for the council, said he had originally told the Priory Park candidates they would appear on the ballot paper as they wished.
However, an approach - from inside the office - prompted a second look at the rules, and he decided it could be unlawful after all.
"If they won they may not be able to take up the seats without further elections," he explained.
"But we have decided to get more legal advice to make sure we are right," he said.
Prittlewell Lib Dem candidate John Adams said he could see no harm in the Independents linking themselves to their cause on the ballot paper.
"It's a local matter, and I'm all for people knowing exactly what they are voting for," he said.
The seven who are standing on the park issue are Adrian McCall (St Laurence), Keith Richardson (Eastwood Park), Michael Downer (Belfairs), Sue Richardson (Southchurch), Doug Copping (Leigh, Don Weedon (Chalkwell) and Peter Walker (Prittlewell).