Mary Creagh MP (Lab, Wakefield) said the move was essential to tackle the "ticking timebomb" of childhood obesity.
She led a delegation to the communications watchdog, Ofcom, calling for the move and has tabled a House of Commons motion, which has a
lready been signed by nearly 20 MPs.
Ofcom is consulting on advertising to children, but has already ruled out a 9pm watershed, similar to the one which stops adult programmes being broadcast during family viewing time. Ms Creagh said: "A 9pm watershed is the only way to stop junk food advertising to children and tackle the time-bomb of childhood obesity."
Restrictions
The motion says "television advertising is the primary way in which junk foods are marketed to children" and that many health and consumer organisations have called for a watershed.
House of Commons motions are used by MPs to raise issues of concern to ministers.
Ms Creagh's Children's Food Bill, due to be considered in Parliament next week, sets out a number of measures to promote healthy eating for children, such as restrictions on the marketing of food to children and a duty on local authorities to promote healthy eating.
Ministers have already taken up some of the bill's provisions, including restrictions on junk food in school vending machines.
