In 1989 Williamson joined "The Times" as a reporter, becoming diary editor (1990--92), then home news editor (1992--95) and Whitehall correspondent (1995--96).
In 1989 Williamson joined "The Times" as a political corespondent with a twioce weekly column. He became diary editor (1990--92), then home news editor (1992--95) and Whitehall correspondent (1995--96).