In 1987, O'Neill met Labour Party Politician Ken Livingstone, and subsequently became his main advisor on Irish issues. In the 1990s, he met and married Kate Hudson, who later became the Chair of the Campaign for Nuclear Disarmament. In 2000, he was appointed as Mayor of London Ken Livingstone's deputy chief of staff, responsible for transport, trade union relations, public affairs and editing The Londoner newsletter. He launched a major celebration of St Patrick's Day in London in 2002, took the lead on congestion charging, and developed links with Hugo Chavez, exchanging transport expertise for cheap fuel.