FOUR hundred Christmas cards and a Christmas tree were among the 'gifts' which arrived at the doorstep of the Governor, Chris Patten, yesterday. Delivered by legislator and unionist Lau Chin-shek, the cards carried a single message - an appeal for government action to get rid of age discrimination. Speaking for the 115,000-strong Confederation of Trade Unions, Mr Lau said age discrimination was common, with workers in their 30s being turned away from jobs. The confederation has found that more than two-thirds of advertisement for salespeople have an upper age limit of 30. It called for the banning of such limits. Representatives of the April 5 group marched to Government House to protest against the Government's withdrawal of the Employment (Amendment) Bill after an amendment by Mr Lau had been endorsed by the majority of Legco. The group said the incident exposed the autocracy of the Hong Kong British Government and violated Mr Patten's promises of a government that is 'open, fair and acceptable to the people of Hong Kong'.