Starmer is backing Southgate's men to overcome their quarter-final opponents on Saturday. "I think they'll beat Switzerland," he also told Virgin Radio.
On what he would say to the players, he added: "I would say, 'just forget where you are in the competition. Forget all the noises off. I have to do this. Just go into a sort of tunnel. Know what you're trying to achieve and just don't listen'."