This is wrong.

A large chunk of the “classic” UK sell-offs were 1980s to early 1990s: BT (1984), British Gas (1986), British Airways (1987), and by 1991 regional electricity and water companies had been privatised.

A lot of EU single-market liberalisation in network industries ramped up later (late 1980s/1990s, and beyond). For example, telecoms EU “competition” directives begin in 1988/1990 and are amended through the 1990s. Meanwhile, the UK government had already announced plans to sell major chunks of BT by 1982, and BT’s privatization was implemented through UK legislation. England/Wales water privatization was created by Water Act 1989.