The San Francisco Board of Supervisors has voted unanimously to enact a new law banning discrimination in employment and housing on the basis of weight and height. Mayor Willie Brown is expected to sign the law, which will then take effect in 30 days. Under the new rules, businesses that contract with the city and violate the law will risk losing their contracts and could be barred from future bidding on city contracts. Tomas Lee, legislative assistant to Supervisor Tom Ammiano, told California Employer Advisor that the law also authorizes civil lawsuits by employees, whether or not they are city contractors. San Francisco would be the fourth jurisdiction in thecountry to adopt such a law, behind Santa Cruz, Calif., Washington, D.C., and the state of Michigan. But legal challenges could be on the horizon, in light of a city attorney opinion that state anti-bias rules supersede the new law.