Labour have reportedly drawn up plans to lower the voting age from 18 to 16 in an attempt to capture more support.
The Sunday Times said Labour's shadow minister for London, Sadiq Khan, had prepared the key reform, which could be introduced for the 2020 election if the party return to power in 2015.
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Nikol Pashinian took office in May after spearheading massive protests that forced his predecessor to step down.
The New Zealand leader addressed the death of the 22-year-old.
The crunch Commons vote takes place on Tuesday.