Complex sentence: The "Toddlers' Truce" (an arrangement whereby there were no television broadcasts between 6 PM and 7 PM, to allow parents to put their children to bed!) is abolished; it has been a major stumbling block to the success of ITV.
Split into simpler sentences: The "Toddlers' Truce" (an arrangement whereby there were no television broadcasts between 6 PM and 7 PM, to allow parents to put their children to bed!) is abolished. It has been a major stumbling block to the success of ITV.