Labour peers are to launch a fresh bid today to force the government to lower the voting age to 16 for the EU referendum.
The House of Lords passed an amendment last month that would have lowered the franchise age from 18, bringing it in line with the Scottish independence referendum held last year.
But the Commons last week voted to overrule the Upper Chamber by 303 votes to 253.
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The government has argued implementing the change would cost around £6m and would be wrong to change the “tried and tested” election franchise for a single vote.
Despite the resistance, Labour has tabled a new amendment to the EU Referendum Bill that would grant 16 and 17-year-olds the vote in the public poll.
The SNP and the Liberal Democrats also back the call to lower the franchise age.
David Cameron has pledged to hold an referendum on the UK's membership of the EU before the end of 2017.
The Guardian reports that Baroness Morgan of Ely, the Shadow Foreign Office Minister, will also challenge the government’s claim regarding the cost of amending the franchise.
Baroness Morgan said last week: "While we were disappointed with the Commons rejection of our original amendment, we believe there is a real appetite among young people to be involved in the EU referendum debate.
"This is the most informed generation ever. They have been prepared for civic participation through citizenship lessons and they are ready to have their say.
"Whether or not Britain remains in the EU is probably the most important political decision of our time. 16 and 17 year olds should be given a voice."
Critics have claimed that amending the voting age is designed to give the pro-EU camp an advantage as they believe young people are more likely to want to remain part of the 28-member bloc.