This is prospective Labour leader Owen Smith on the Andrew Marr show this morning, explaining why he’ll be one of the 65% of Labour MPs voting in favour of the renewal of Trident next week:

Let’s just see if we can get this straight once and for all.

1. Labour wants to spend £200bn on a new Trident system so that it can then scrap it as soon as possible in multilateral disarmament talks, (incurring billions of pounds more in decommissioning costs), with a supposed long-term goal of completely eliminating all nuclear weapons on the planet.

2. That’s a bit like buying a Ferrari to replace your Ford Focus because you want to reduce carbon emissions by putting it in a car crusher. But weirdly, the last time a Labour government attempted to bring about some multilateral reductions, the idea of total disarmament was completely ruled out as “non-negotiable”.

3. Owen Smith tells us that we need Trident because the world has become a more dangerous place. (We’ll generously gloss over the finer details of exactly how he plans to use nukes to defeat ISIS.) This, presumably, is why successive Labour and Tory governments have reduced the capability of the existing Trident fleet by almost half, first from 200 warheads to 160 and then from 160 to 120.

4. Labour wants the UK to have the strongest possible nuclear arsenal in order to use it as a bargaining chip in disarmament talks at some unspecified future date. The UK’s 120 warheads represent approximately 0.7% of the world’s current stockpile, so Labour’s position must be that it can leverage those 0.7% in order to bring about the removal of the other 99.3%.

Labour, then, is telling us that for every one warhead the UK decommissions, it can persuade the rest of the world to give up 142. We commend their ambition, and can only imagine that Labour are AMAZING at poker.

(We’re not aware of any cuts by other powers as a quid pro quo for the UK’s recent reductions from 200 warheads to 120, incidentally.)

5. Labour MPs and MSPs in constituencies with nuclear weapons installations, such as Jackie Baillie in West Dunbartonshire and John Woodcock in Barrow, simultaneously insist that the reason the weapons must be retained is to protect astronomical numbers of supposed jobs reliant on them.

Yet at the same time we’re told that the ultimate objective is to get rid of the weapons. So the goal is to keep the jobs in order to work diligently towards losing them again, rather than using the money to create jobs which would be sustainable in the long term.

That’s a bit like investing all your savings in Betamax video recorders the day after the DVD player is invented.

6. Even if we accept the wildest estimates of such MPs regarding the number of jobs reliant on Trident – which range from around 500, according to the MoD, up to absurdly inflated claims of over 20,000 – the lifetime cost of the system is expected to be in excess of £200 billion. That’s £10m per job over the 40-year period, or £250,000 per job per year.

We suspect that if you offered every employee dependent on Trident £125,000 a year for life to sit at home and watch box sets of Game Of Thrones, they’d snap your hand off. But instead Labour’s policy is to spend twice that much while ensuring that the employees get paid much less, and while trying its hardest to destroy their jobs.

So, in summary: get rid of nuclear weapons by buying more of them, in order to protect jobs by trying to get rid of them, because the world has become more dangerous so we have to give our weapons away. Have we missed anything?