Re: A bit closer to home
As others have said, Sundog, being the 5th or 6th biggest is no use when you have to deal with the biggest. If you're on level-pegging with them then there's a quid-pro-quo. If they're 10x the size of you then they impose their will.
Scale that down if you will, and maybe we want to deal directly with Mexco - get some tequila in. Sure, by ourselves there's a reasonable option for coming up with a fair deal where both sides are balanced, but (if I may be selfish for a moment) right now we're negotiating from the position of the leviathan. We don't need to put up with anything from a market the size of Mexico that we don't want to. So whilst we could strike a fair deal with them by ourselves, right now we could strike a deal heavily in our favour. So in that event, costs go up, standards go down, or some mix of the two.
No offence to Mexico - I just picked a country with a similar GDP to the UK.
And if you want to say we're the "5th or 6th largest economy", pick one and back it up. My evidence says the 9th, and one of the 8 above us is another EU member.
https://www.cia.gov/library/publications/the-world-factbook/fields/208rank.html
Here we can see that the EU is the second biggest after China (10% below, with the USA 10% below that). India, in fourth, is half the size of the US economy. These numbers are pretty close to the CIA ones, so they should be fairly representative of fact.
The UK on that scale is <15% of the USA. If you think we can argue on a level playing field there, you're deluded by the history of Empire.
And if your first kneejerk is to call someone a cretin, bring evidence or fuck off home, you fucking melt. I'm so fucking tired of having this argument with people who seem to think that "belief" is a fungible currency when it comes to trade negotiations, or that the world owes us a favour because we used to own half of it...