Labour's Emily Thornberry has labelled the Tories and DUP a "coalition of cavemen" for opposing the lowering of the voting age to 16.
Standing in for Labour leader Jeremy Corbyn at this week's PMQs, the shadow foreign secretary argued: "There is no logical principled objection to votes at 16."
She said that the movement had support from both the Scottish and Welsh governments, PoliticsHome reported.
"Every party in this House supports it, except of course the Conservatives and the DUP," Thornberry continued. "Once again, joined in opposition to change, they're not the coalition of chaos, they're the coalition of cavemen.
"Why doesn't the [Cabinet Office] minister [David Lidington] realise the lesson that we women taught his predecessors 100 years ago? When change is right it cannot be resisted together and this is a change whose time has come," Thornberry said.
Lidington - standing in for Theresa May who is visiting China - told Thornberry to "grow up". He noted that 26 out of 27 of the other members of the EU, plus the US, Canada, New Zealand and Australia all set their voting age at 18.
This is the normal age of majority, he argued, and one that was "perfectly reasonable".
The Labour minister said that 16-year-olds were allowed to marry, join the armed forces, work and pay taxes. Citing government figures, she also noted that the number of 16- and 17-year-olds receiving carers allowance had risen by more than 50% over the past four years.
"How can it be fair, how can it be logical to expect them to take on that responsibility because of failures of the state and then deny them a say on how that state is run?" Thornberry asked.
Lidington retorted: "It was the last Labour government that raised the age to buy cigarettes, raised the age to buy knives to 18, raised the age to buy fireworks to 18 and raised the age to buy sunbeds to 18. If she wants to talk about inconsistency she might as well look at the mirror."
George Eaton of the New Statesman noted on Twitter that Labour would be the big winners of change:
While Labour was the most popular party among the youngest voters, new research indicates that the widely reported "youthquake" was a myth. The British Election Study report said said there was no surge in youth turnout in support of Jeremy Corbyn.
Speaking to IBTimes UK, Darren Hughes, chief executive of the Electoral Reform Society, said, "Whenever there is a discussion about the franchise, it can make the parties nervous; they think about the coming election, what it might mean, and what happened previously. In general, we should think about what this might mean over the decades."
"There is no reason why any party, whether centre-left or centre-right, couldn't persuade young people to vote for them. I think it is a mistake for parties to assume that all young voters will vote the same way," Hughes said.
Hughes said he believes parties should "look to the horizon rather than looking at your feet".
The issue of votes at 16 was the dominant theme in this week's PMQ exchanges. The other highlight was a robin trapped in the House and flying above MPs' heads as they tried to debate.