MI5 and counter-terrorism police missed chances to prevent the 2017 Manchester Arena attack through a series of failings in the handling of the case of the bomber, Salman Abedi, a parliamentary watchdog has concluded.

Abedi detonated a homemade bomb in the foyer of the arena on 22 May last year as an Ariana Grande concert came to an end, killing himself and 22 other people, and injuring more than 100.

In a report on the five terrorist attacks in England in 2017, the intelligence and security committee (ISC) singled out the handling of Abedi’s case by MI5 and counter-terrorism police for damning criticism.

“What we can say is that there were a number of failures in the handling of Salman Abedi’s case and, while it is impossible to say whether these would have prevented the devastating attack on 22 May, we have concluded that, as a result of the failings, potential opportunities to prevent it were missed,” said Dominic Grieve, the Tory chair of the ISC.

The report also criticised the Home Office over its failure to cooperate with the committee’s inquiry into the Parsons Green tube attack in September last year, in which more than 50 people were injured by a partially exploded bomb left by Ahmed Hassan, an Iraqi-born teenager.

Among failings highlighted by the committee in the Abedi case were:

• MI5 and counter-terrorism police failed to take any follow-up action after Abedi visited a known extremist contact in prison, previously named in media reports as Abdal Raouf Abdallah, who was jailed for trying to help people travel to Syria to fight with militants.

• MI5 did not place monitoring or travel restrictions on Abedi, which allowed him to return to the UK undetected in the days immediately before the attack.

• Abedi, a subject of interest to MI5 but not under active investigation, had been flagged for review by the security service but its systems “moved too slowly” and the review did not happen before the attack.

• Abedi was never considered for referral to the Prevent programme.

The report said there was one issue that caused “serious concern” but could not be revealed due “highly sensitive security aspects”, but would be raised with the prime minister in a classified report.

The ISC also raised two broader issues that played a part in two or more of the attacks: the “out of date” system for regulating the purchase of explosive ingredients, which has since been overhauled, and the failure of communication service providers (CSPs) to stop their systems becoming a safe haven for extremists.

The Times reported that committee also called on ministers to lobby advertisers to boycott technology companies such as Facebook and Google until they show they were serious about tackling online terrorist material. Abedi bought ingredients for his bomb from Amazon and watched a YouTube video before assembling it.

In the Parsons Green case, the committee said that despite multiple requests the Home Office failed to provide full evidence in time for it to be included in the inquiry.

Grieve said: “This is unacceptable. From what we have seen to date, there were fundamental failings in the handling of this case by the Home Office, the police and Surrey county council.

“This litany of errors will require a separate comprehensive review to which the Home Office must be directly answerable.”

The committee said monitoring vehicle hire must be a significant element of counter-terrorism operations in the future. The Westminster bridge attacker, Khalid Masood, and one of the London Bridge jihadist terrorists, Khuram Butt, hired vehicles before carrying out their attacks.

“Currently, incompatible systems and limited capabilities are hindering progress in this area,” the report said.

Last year’s attacks revealed there were still problems around the sharing of information by MI5 with the police, which the committee has flagged in the past.

Responding to the report, the home secretary, Sajid Javid, said: “Following the attacks, the government, police and MI5 undertook a series of rigorous reviews to ensure we are all doing everything we can to tackle the evolving threat of terrorism.

“As a result, we have updated our counter-terrorism strategy, introduced new legislation to allow threats to be disrupted earlier and have increased information sharing with local authorities. We are also ensuring technology companies play their part by stopping terrorists from exploiting their platforms.”

The national head of counter-terrorism policing, assistant commissioner Neil Basu, said: “There will be further scrutiny and examination into the circumstances of these attacks, including coronial inquests and other potential criminal proceedings, which may preclude us for the time being from commenting publicly to some specific points raised.

“In the meantime, we would like to reassure the public that ever since the attacks of last year we have sought to learn from what happened before, during and afterwards, and improve our wider operating model and ways of managing and mitigating the risk from terrorism.

“We will not let the terrorists who carried out these appalling attacks succeed in scaring and dividing us. Working ever more closely with the security service and learning our lessons, we will do everything we can to reduce the chances of this happening again.”

Diane Abbott, the shadow home secretary, said: “It’s shocking to learn the terrible terrorist attack on the Manchester Arena could have been prevented.

“This raises serious questions for the entire policing and security system, not simply MI5 alone. These questions include the proper identification, prioritisation and prevention of terrorists, which is an increasingly integrated process, involving multiple agencies, or at least it should be.

“But this government has undermined policing with cuts of 21,000 officers. And community policing, the frontline ears and eyes on the ground in the fight against terror, has been hardest hit.”