A CONCERN group for the elderly has asked the Government to review a social security assistance scheme which became effective yesterday. Six members of the Association for the Rights of the Elderly petitioned Government House, urging Governor Chris Patten to fulfil a pledge they said he had made in a policy speech last October. Holding a banner of ''Governor telling lies, promise not honoured'', they said Mr Patten had promised a 15 per cent real increase in public assistance this year. The Social Welfare Department said an undertaking had never been given for 15 per cent across the board increases. Recipients get four to 36 per cent more under the new scheme. An elderly person now gets $1,550 a month, excluding the old aged allowance of $510 a month which remains unchanged. But group members said the elderly would be hard hit by a corresponding increase in welfare charges such as hostel fees. Leung Sui-ying, 76, a widow who lives alone in a 150 square feet unit at the Lower Shekkipmei Estate, was sceptical about the Government's public assistance scheme. ''I receive an old age allowance of $510 a month, but $289 already goes to paying the rent. ''I have hardly enough to buy food, and I can only have some vegetables or preserved egg yolk for my meals.'' She did not apply for public assistance because she had been told if she did so she could not go to the mainland as frequently as she did. ''My mother is there,'' she said. ''She used to live here but had to move back to our village in the mainland because we cannot live on two sharing an allowance.'' Benefits will be suspended if a public recipient leaves Hongkong for more than 45 days, but this has been relaxed to 180 days for elderly. Mrs Leung also believed the incorporation of old age allowance into public assistance received by a family would not work and would cause quarrels. ''There is no way for the elderly to receive their share through their sons and daughters,'' she said. Her own children only provided minimal support for her, said Mrs Leung.