MI5 made "serious misjudgements" in its assessment of the threat facing UK citizens ahead of October's terrorist atrocity in Bali, a report by a committee of MPs has found.

Had they passed on these warnings properly my brother would be alive today Tobias Ellwood Victim's brother

It is also highly critical of the way the Foreign Office issued travel advice, finding it failed to "accurately reflect" the level of terrorist threat.

The report makes clear the intelligence services had no specific information about the timing or location of the Bali bomb.

But they say errors were made in the way the risk of an attack in Indonesia was assessed and communicated to the public.

And as thousands of people are preparing to go abroad for Christmas, the MPs say the Foreign Office is still giving confusing advice to travellers.

Foreign Secretary Jack Straw has pledged a comprehensive review of his department's travel advice in the light of the MPs' findings.

'Potential target'

But relatives of bomb victims are angry and believe clearer warnings may have saved lives.

The report, by the Commons intelligence and security committee, said developments earlier this year - including a failed grenade attack on a US diplomatic residence - should have led MI5 to reassess the security threat in the country as "high", rather than "significant"

Straw admitted travel advice could be improved

"A threat existed to western tourists in Indonesia; the largest concentration of western tourists there is on Bali; and they gather in large numbers in a limited number of nightclubs," the report adds.

"These facts should have been recognised by the Security Service (MI5) as pointing to a potential target.

"This was a serious misjudgement and meant that the Security Service did not assess the threat correctly and, therefore, raise the level of threat to high."

Urgent changes

Mr Straw told MPs he would be studying the report's findings before issuing a more detailed response.

But he said the committee had backed up his assertion that there was nothing the UK or its allies could have done to prevent the attack.

And he promised urgent changes in the way the Foreign Office issues security advice to travellers.

Victim Neil Bowler was based in Singapore

Mr Straw said: "Changes have been put in hand post-Bali, some changes preceded that.

"But given the nature of the committee's report those changes are now likely to be accelerated and made more thorough."

Tobias Ellwood, whose brother Jon, 39, was one of more than 200 people killed, said he was "shocked" and "aghast" at the report.

"Our family are still coming to terms with it all, however we are very upset to hear that the threat level had not been increased.

"We understand the intelligence service could not have prevented the bomb, but had they passed on these warnings properly my brother would be alive today because he just would not have gone to Bali."

Ancram: 'Lessons have not been learned'

Andy Bowler who lost his brother Neil, 27, said his family had not ruled out taking court action against MI5.

Mr Bowler, 25, said: "If the secret services gave the information properly, then he could still be alive today.

"They made a very, very clear mistake and they should be brought up for it."

In the days following the Bali bomb there was a dispute over what warnings had been issued.

Confusion

The UK Government issued a "generic" warning of an attack in Indonesia on the Foreign Office website on 27 August, but this did not mention Bali by name.

It came after a warning from US intelligence about possible attacks in several "hotspots" including Bali.

Conservative shadow foreign secretary Michael Ancram urged the government to act "swiftly" on the MPs' findings to restore public confidence.

He suggested the Australian Government had learned the lessons of Bali more quickly than the UK.