Television viewers face more advertising during prime-time shows under a major EU shake-up of rules around commercials to help broadcasters who are losing viewers to online services such as Netflix.

The European Commission announced proposals to liberalise rules capping television advertising at 12 minutes per hour.

They will be replaced with a daily limit of no more than 20 per cent of advertising between 7am or 11pm, allowing broadcasters to “choose more freely” when they place their adverts.

It could result in broadcasters extending their most expensive advertising slots during hit-rated shows such as The X Factor and Downton Abbey, while cutting them during day-time broadcasting.