Has Tories' independent-minded MP put the party off open primaries?

It was supposed to be one of the Coalition's landmark ideas for admitting ordinary voters to the often closed world of party politics.

The new Government committed itself to stage US-style "open primaries", where local people choose election candidates, in 200 safe seats.

But it emerged yesterday that ministers are backing off from the radical electoral experiment, with the Cabinet Office only saying it was contemplating "how to take forward this policy".

The official explanation for the delay is that the Government is awaiting the outcome of the review which will cut the number of Westminster constituencies from 650 to 600. But there could be more pragmatic motivations – money and self-interest – behind any retreat. It cost the Conservative party £40,000 to stage a primary in 2009 to select a candidate in the Devon constituency of Totnes. If the Government pays for 200 similar exercises, the taxpayer could be left with a bill for £8m. Moreover Sarah Wollaston, the winner in Totnes, and now its MP, has proved to be an independent-minded thorn in the flesh of the Tory leadership. Dr Wollaston was among 81 Tories who demanded a referendum on Britain's place in the EU and even turned down a job as a ministerial aide.

Ahead of her selection, David Cameron described primaries as an "exciting opportunity" to engage with the voters and the Coalition Agreement promised: "We will fund 200 all-postal primaries over this Parliament, targeted at seats which have not changed hands for many years."

Since then nothing has happened. The Cabinet Office said yesterday: "The boundary changes legislated for in 2011 will have implications for almost all existing constituencies and we will need to take this into account as we continue to consider how to take forward this policy."

Dr Wollaston told BBC Radio 4 that primaries would "change Parliament for the better".

She added: "The whole point of an open primary is to demonstrate you can bring people into politics from non-political backgrounds and bring their experience to bear."