Unelected PMs must call poll within 6 months - Cameron
David Cameron: "The politicians would love" a hung parliament
David Cameron has proposed that anyone who takes over as prime minister mid-way through a Parliament would have to hold an election within six months.
The Conservative leader has been a critic of the way Gordon Brown took over from Tony Blair and spent three years as PM without an election.
John Major and Jim Callaghan also both took over as PM outside of elections.
Mr Cameron unveiled his political reform plans in Essex before attending his 38-year-old sister Clare's wedding.
Miss Cameron, who introduced her brother to his wife Samantha on a family holiday, married market research executive Jeremy Fawcus at a private ceremony in Peasemore, Berkshire.
The Conservative leader's daughter Nancy, six, was a bridesmaid and four-year-old son, Elwen, a page-boy.
During the morning's campaigning, Mr Cameron's key proposal was that anyone taking over as PM following the death, overthrow or resignation of the previous incumbent would have to call an election within six months.
A new PM would be free to request a dissolution at any time during the six-month period, which would allow time for him or her to appoint a ministerial team and set out a programme for government and for Parliament to deal with any outstanding business, under the plans.
"It means putting the people in charge, I believe you should be in Number 10 because people have voted for you," he said.
Mr Cameron also unveiled plans to provide state funding for 200 all-postal primaries to select parliamentary candidates across the country over the course of the next Parliament at a total cost of about £8m.
The ceremony was in Mr Cameron's childhood village of Peasemore, Berks
The money - which would come from cutting the amount spent on the Electoral Commission - would be divided up according to the share of the vote parties had in the general election.
Parties would decide which constituencies they want to hold open primaries in, select four or five candidates and then send ballot papers to all registered voters - regardless of whether or not they back that party - for them to select their election candidate.
Mr Cameron also attacked the idea that a hung parliament could deliver significant change for voters.
He said the resulting bargaining between politicians would not bring benefits on issues including the economy, crime, immigration or control of the political process.
Addressing those who felt a hung parliament might make a change in itself, he said: "There is one group of people who would love a hung parliament and that's the politicians.
"They can sit in Westminster, they can haggle - I'll have this job, you have that office, bit of pet spending on my project over, bit of pet spending on your policy over there.
"The politicians would adore it. The people who would be let down are those who want to keep interest rates low and get our economy going."
Meanwhile shadow chancellor George Osborne also warned on a hung parliament and said the Conservatives would next week focus on the economy.
"People know Labour have failed and all they offer is a jobless recovery from a weak government," he said.
"Only a Conservative majority will bring the leadership that we need to deal with our debts and get the economy working for everyone."
The party has unveiled its latest set of posters which feature Mr Cameron in a white shirt - sleeves rolled up - in front of a crowd at a political rally.
The slogans read: "Let's scrap ID cards", "Let's restore discipline in schools", "Let's fund new NHS cancer drugs" and "Let's have National Citizen Service for 16-year-olds".
They will appear on 2,200 billboards nationwide from Monday.
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