The PM campaigned to stop us leaving the EU, then he spent years on the Labour frontbench trying to prevent a clean Brexit.
This new Labour Cabinet has made no secret of their dislike for the new US President - with even Foreign Secretary David Lammy branding him “xenophobic” and “no friend of Britain”.
But Sir Keir will have to embrace Brexit and Donald Trump fully if he wants to kickstart our economy.
Over in the US, Trump is appointing his top team and considering what countries to hit with massive import tariffs. We must avoid being at the wrong end of any trade war with America. Thanks to Brexit we can be. Our relationship with America is special, but it is not just about sentiment. It is about cold hard economics.
The US is the UK’s single biggest export market, the UK is one of the biggest investors in the US, and the US is the biggest investor in the UK.
We simply cannot afford to risk this lucrative trade.
The good news is that I believe Trump remains very pro-British - and much more so than President Biden. Finally we have someone in the White House who would like to do a trade deal with Britain.
I don’t just think this - I know it. Because I met Donald Trump when he was US President last time and he told me so. It was 2019 when I went to see President Trump in the ambassador’s house in London during his state visit. The most powerful man in the world had an unexpected slot open up in his diary.
So me and two other MPs went to see him and pitch for a trade deal. Our idea was simple but effective. Britain and the US should strike a sector-by-sector deal first - leaving the more difficult areas to be closed at the end. That way we could unlock billions in trade as we went, and gradually build up to a full blown bells and whistles agreement.
Trump is the master deal maker. He was attentive and immediately grasped what we were saying; his desire for a trade deal had got bogged down in Bureaucratic haggling - but there was a way out.
He couldn’t have been clearer from the get-go that he wanted a trade deal. At the end, he looked at us and said, “I like you guys, we’re going to do your deal”, before leaving to get changed for the State Banquet.
I confess we felt a frisson of excitement. Had we just done the deal others said was impossible? We were brought back down to earth by the ambassador - the excellent Woody Johnson - who reminded us that we had not actually closed the deal as we were not actually negotiating for the government. Close but no cigar.
But we had discovered something very important: Trump wanted to do a deal. If you get in front of him with a good pitch, history could be made. We walked away with a real sense of his deep respect and affection for the UK and his desire to ‘do the deal.’
Sadly, Joe Biden put a stop to serious trade discussions. But now Trump is back there is a new opportunity.
Over the next few months and years, Sir Keir Starmer will face a stark choice. Many in Labour will tell him to pivot away from the US and cosy up to the EU instead. They will want him to unpick Brexit to trade more with the continent. He must ignore them.
A crossroads lies ahead: more trade with Trump’s America, or unpicking Brexit and cosying up to the EU. The PM must pick enhanced trade with America not crawling back to the EU. Siding with the EU in a tit for tat tariff war is the wrong move, Brexit gives us a real alternative and we can avoid them.
It is imperative Sir Keir gets alongside the new President and makes a trade deal a priority. After all, the US is the most important market for the UK’s services and goods.
Just look at the relative GDP of the USA and the Eurozone. In 2008 the US and the Eurozone economies were both approximately equal in size at about $14Trillion in today’s prices.
Now, the Eurozone languishes at $15TN while America's stands at $26.9TN. Instead of a trade war, we must now seek that trade deal, for the sake of all our citizens.
This new Labour government needs to rise above the petty hatreds it has fostered in its public utterances on President Trump, swallow its pride and deepen those historic ties with the US, there will never be a better time to do it. A trade deal with the US should, even for David Lammy be a no brainer.