Britain's government, parliament and political parties spent decades turning "a blind eye" to high-profile child sex abusers and sometimes actively protected them, an investigation reported Tuesday.

A former Liberal party leader announced his resignation from the House of Lords after the report condemned his failure to act against a paedophile MP from his party.

The government-commissioned report into how Westminster institutions dealt with abuse claims found a culture of deference by police, prosecutors and parties towards politicians. It also noted a widespread failure to put the needs of children first.

"It is clear to see that Westminster institutions have repeatedly failed to deal with allegations of child sexual abuse, from turning a blind eye to actively shielding abusers," said the inquiry's chairwoman, Alexis Jay in a statement. "A consistent pattern emerged of failures to put the welfare of children above political status, although we found no evidence of an organised network of paedophiles within government."

However, the Independent Inquiry into Child Sexual Abuse found no evidence to support reports in recent years of a coordinated "paedophile ring" involving senior political figures. In the 1960s, 1970s and 1980s, MPs including the Liberal Cyril Smith and Conservative Peter Morrison -- both later knighted -- "were known to be active in their sexual interest in children, but were protected from prosecution".

In 1969 Smith admitted allegations he sexually abused teenage boys, but was not prosecuted. Ten years later, the then Liberal party leader David Steel discussed the issue with him but took no action.

Former liberal leader quits parliament

Steel resigned his position in the upper parliamentary chamber, the House of Lords, on publication of the report Tuesday. "I shall now stop the weekly travel from Scotland to London and enjoy a quiet retirement from public life," he said. "Not having secured a parliamentary scalp, I fear that I have been made a proxy for Cyril Smith," he said in a statement.

The report meanwhile found that senior officials in the Conservative party knew about allegations against Morrison, an MP who later became a government minister, "but did not pass them to police". "These are examples of a political culture which values its reputation far higher than the fate of the children involved," the report concluded.

Jay said things had changed, but said it was "unacceptable" that some political parties still today had no specific child protection politics. As recently as 2017, a prospective MP for the Green party appointed her father as an election agent despite him having been charged -- and later convicted -- of raping a child. She was not elected as an MP.

In a statement, Home Secretary Priti Patel paid tribute to the "strength and courage of the victims and survivors who have shared their experiences. "The government will review this report and consider how to respond to its content in due course," she said.

The Independent Inquiry was commissioned in 2015 in the wake of a series of high-profile sex abuse scandals, the most prominent of which involved the late BBC TV presenter Jimmy Savile. Westminster came under the spotlight following claims by a former charity worker, Carl Beech, that he been raped and abused by several famous political figures in the 1970s and 1980s.

It turned out he was lying, and last year Beech was jailed for 18 years for perverting the course of justice, fraud and possession of indecent images.