The Brussels terrorist attacks are not a surprise, a member of the intelligence services watchdog has said.

Norfolk MP Keith Simpson, who joined the Intelligence and Security Committee last year, warned that the security services would not be able to prevent every attack.

'These terrorists are highly sophisticated. Even our intelligence and security services, which are some of the best, a lot of what they do to protect us we don't see. In the last year we have frustrated or stopped at least seven attacks on the UK directly or British citizens overseas.

'But as the IRA once said 'we only have to get lucky once'. The odds are not good. The objective of these people is to terrorise and I think on the whole we respond to this threat pretty well.'

He said the Belgian authorities raised the alert about further terrorist attacks, adding: 'What it says is just how important it is for every European country to have well-integrated intelligence and security agencies that cooperate closely together because these terrorist groups range across our continent. Some are sadly home grown, some have managed to get in through forged documents,' he said.

But he said Britain was well prepared if there was an attack.

'The kind of terrorist attacks we had ten years ago [the July 7 underground bombings]. What we put in place was a system by which we have integrated MI5, MI6, GCHQ and they work very closely together. Their personnel are embedded in each others' organisations. I am not sure that is the same in every European country. Of course we have an infrastructure through the National Security Council in which the intelligence and security organisations, and the police, work together with the prime minister, the home secretary and others and also very importantly because of our experience we rehearse what happens if there is a terrorist attack.

'There was one such big exercise in the last three weeks imagining another attack on the underground.'