Shares of London-listed oil firms fall after Labour touts tax

LONDON (Reuters) - Shares in some London-listed oil and gas producers including Tullow Oil , Premier Oil and Cairn Energy fell on Thursday after the main opposition Labour Party pledged to raise taxes on the sector if it wins a Dec. 12 election.Labour said in its manifesto it would introduce a "windfall" tax on oil companies "so that the companies that knowingly damaged our climate will help cover the costs."It added it would safeguard jobs and skills that depend on the offshore oil and gas..