Labour is set to reignite the political row over selective education by making it easier for disaffected parents to force the closure of their local grammar schools.

Jim Knight, the schools minister, has instructed officials to look at how to simplify the balloting process by which schools can be forced to drop selection under a 1998 law.

Knight’s move will be seen as an attempt partly to appease the Labour left and partly as a ploy to reopen a split in the Tory party over selection that emerged this summer. David Willetts, then shadow education secretary, said the 11-plus exam “entrenches advantage”.

The balloting system is a complex three-stage process that requires 10 parents to trigger a petition which must then be signed by 20% of all parents in the affected area before a full local vote takes place.

This has proved so complicated that only one full ballot – in Ripon, North Yorkshire, in 2000 – has gone ahead. It failed to end selection at the local grammar school.

“We are firmly committed to giving local parents the right to vote to abolish selection at existing grammar schools,” said Knight this weekend. “It is absolutely right we keep the parental ballot arrangements under review to ensure they work effectively and give value for money.”

Another Whitehall source said: “The system was criticised by the education select committee in 2004 when they said the system was ineffective.

“Now Jim has signalled that the focus is returning to grammar schools. It is a recognition that there are issues that need looking at.”

Officials are expected to complete a review of the balloting arrangements by the end of the year.

Labour has previously been accused of using grammar schools as a political ploy. Before the 2005 election, Charles Clarke, then education secretary, signalled he was planning to reexamine the rules, but no changes have been made.

In addition to shortening the process required to trigger the full ballot or lowering the number of petitioners required to trigger it, another option now under consideration would be to allow antigrammar school campaigners early access to a full database of parents eligible to vote.

This could require MPs to change laws on the electoral register and on data protection, requiring a debate in parliament.

England’s remaining 164 state grammar schools have become a totemic issue dividing left and right. Many Tories see them as vital to a meritocratic society but supporters of comprehensive education claim grammars are a bastion of privilege which “cream off” the brightest pupils and damage other state schools.

David Cameron has promised that existing grammars would be safe under a Tory government but that no new ones would be built in areas that did not already have them.

Michael Gove, shadow children’s secretary, said yesterday: “Instead of fiddling around with the rules on ballots, why don’t the government simply back good schools and concentrate on spreading good practice?”

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