After months in which what Labour news there has been (if any) was about infighting and cock-ups, finally the last few days have seen some policy announcements from the Opposition.

The Labour leader has revealed plans to fine big companies which pay late (though he used figures disputed by the firms he criticised in his speech). The Shadow Education Secretary has pitched the idea of giving free school meals to all primary school pupils (though in practice that would mean diverting money from education into subsidising the nutrition of better-off children). Corbyn has pledged to raise the National Living Wage to £10 an hour, fulfilling our warning that Osborne’s decision to bypass the Low Pay Commission would open a politicised bidding war (though Labour is yet to explain how the overstretched social care sector would afford further increases in staffing costs).

And yesterday, John McDonnell joined the policy barrage by offering a ‘pensioner’s pledge’ – promising to keep the pension triple lock and to protect the Winter Fuel Allowance. The Shadow Chancellor’s intent is clear – he hopes to make up some ground in a weak Labour demographic by offering money to older voters, and to open a gap between his party and the Conservatives, who have carefully avoided specific promises on either policy.

It’s not a surprising move. Labour is always more likely than its opponents to offer to splash cash – though even Ed Miliband used to accept that the richest pensioners shouldn’t receive money for their energy bills. But it does press at a tender spot in Conservative thinking. Cameron and Osborne bent over backwards to appeal to older voters, who are far more likely to turn out on polling day than their grandchildren, and the topic was almost taboo around the Cabinet table under the previous Conservative leadership.

After years of treating pensioners’ incomes as a sacred cow, it isn’t hard to imagine that some in the Government’s ranks might be nervous about the political risks of going into a General Election offering less money than the Labour Party. But Theresa May and Philip Hammond must not allow Labour to scare them off doing the right thing. These policies have more than worked; they have helped to drive pensioners’ disposable incomes above those of working age households, and in doing so have become vastly expensive for the taxpayer.

We keep saying it, but it bears repeating: this country still has a large deficit, which must be eliminated. The Chancellor was right to caution in the Autumn Statement that after this Parliament he will “review public spending priorities” in terms of “rising longevity and fiscal sustainability”. Endless above-inflation rises to the state pension for a growing demographic are not sustainable when we are still borrowing tens of billions of pounds a year.

Leaving aside fiscal sustainability, there is also the question of justice for the young. The incomes, savings and home ownership prospects of the young are far too poor. The ConservativeHome manifesto urged that tax and spending decisions should prioritise the young, and the rationale for that argument has not changed. With limited money, the time is coming when a decision will have to be made as to who is in greatest need: pensioners who have benefited from the triple lock, or young people who have faced freezes and cuts to the aid available to them from the state?

There are encouraging signs that the Prime Minister sympathises with the challenges facing young people. On her first day, she listed the fact that “if you’re young, you’ll find it harder than ever before to own your own home” as one of her “burning injustices”. We hope she addresses that and other aspects of intergenerational injustice.

As part of tackling that injustice and the deficit, the triple lock should go at the next election. Labour’s pledge is opportunistic, expensive, and unjust. The Conservative Party should make that case, appealing to pensioners’ hopes of better lives for their grandchildren. We should also have confidence that Labour’s huge unpopularity among older voters – founded on its fiscal irresponsibility, its continued confusion about Brexit, its dislike of patriotism and its closeness to terrorists – is robust enough to survive the Opposition’s offer.

In Lord Ashcroft’s latest poll, released a few days ago, only eight per cent of voters over the age of 65 said Jeremy Corbyn would make a better Prime Minister than Theresa May. The Conservatives enjoy a 53 point lead on the economy, a 62 point lead on the deficit, and a 56 point lead on Brexit among the same age group. Any older voter who might find Labour’s ‘pensioner’s pledge’ tempting would have to overcome their general distrust of Corbyn on just about every major issue before it would sway their vote. Armed with that knowledge, the Conservatives should take heart and do what is right.