Lord Mandelson is a poor choice for this job. Our current Ambassador pulled off getting an appointment for the PM and Foreign Secretary to see Donald Trump shortly before his victory and did her best to help Lammy move on from his offensive remarks. She could have continued for longer.
Lord Mandelson is said to be experienced and charming. He will need to be both to win over the President. He will come to crucial trade issues from the EU standpoint that is likely to inflame the President and will probably urge Starmer to align with a losing and no growth EU. To prove me wrong he should begin by persuading the PM to cancel negotiations to give away the Chagos. This is a clear policy where the U.K. and US interests are the same. The absurd and expensive surrender line from the Foreign Office needs to be dumped.
The U.K. has a great opportunity to clinch a free trade deal with the US whilst the EU and the US impose more tariffs on each other. The U.K. should not copy the EU plan to impose high and wide ranging carbon based tariffs under the so called carbon border mechanism.