Teenagers will be told to "stand up for their elders" on public transport-or risk losing their right to free travel. London Mayor Boris Johnson will (26) plans today to make youngsters sign a " (27) pledge" to promise to behave in a (28) manner when travelling in the capital. The three-point pledge states that they will give up their seats to the elderly, (29) and disabled; refrain from using (30) or threatening language; and be courteous and polite to fellow passengers and staff. Those who refuse, or are caught behaving in a rude manner, will have their free travel passes (31) . The plan-a key part of Mr. Johnson’s re-election bid-will initially affect the 400,000 ll-to-l5-year-olds in London who qualify for free travel cards, but Conservative sources believe the idea could be used across the country. A Conservative insider said, "The initiative (32) the push to create a Big Society. It is about changing culture and (33) around behavior to improve the atmosphere on buses and trains for everyone. Speaking before today’s launch, Mr. Johnson said he (34) tackle the anti-social behavior of a "minority of youngsters" on public transport. "When I was a boy, I was taught to stand up for those less able to," he said. "Youngsters enjoy the privilege of free travel, which is paid for by Londoners, but they have to understand that with that privilege comes responsibility." Anyone who abuses this privilege will have it taken away, and will have to earn that right back. Teenagers who are found (35) violating the new behavior code will lose their travel passes. They will have to carry out unpaid community work to have them restored.