Despite possessing the best passing statistics in Europe last season and excelling again in the Barclays Premier League this year Britton has not had a senior call up.
Williams told the Daily Mail: "I thought he should have had a call up last year and I was surprised that he didn't. It is nothing to do with me as someone who plays for Wales, but if you ask my opinion I think he is one of the very best midfielders in the country.
"That goes for this year and last year. How often does he have a bad game? He definitely deserves a call up."