THE Legislative Council's nationality sub-committee yesterday again urged the British Government to grant full citizenship to all 7,000 ethnic minorities in the territory and the 25 wives and widows of former servicemen. The sub-committee called for support for Liberal Democrat peer Lord Bonham-Carter's backbench bill when they met the Minister of State on Hong Kong affairs, Alastair Goodlad. ''We asked the British Government to support the Carter bill,'' convenor Emily Lau Wai-hing said. ''Failing that, we hope they give Conservatives in both houses a free vote. Over moral issues, sometimes the ruling party tends to allow its members a free vote.''