Conservative party conference
Britain's Prime Minister Theresa May speaks at the annual Conservative Party Conference in Birmingham Toby Melville/ Reuters

Two days before this frenetic, volatile election, Theresa May was asked sharp questions by journalists and voters about the recent terrorist attacks and how they might have been avoided. She looked uncomfortable, furious, her face contorted in the most alarming way.

The strong and stable lady seemed unprepared for the sudden focus on policing and security, both of which she has been in charge for seven years. So what did she do? She resorted to a flustered politician's easy fix – populism.

Mrs May pledged that, if elected, she would withdraw the UK from the European Convention on Human Rights (ECHR) and shred the Human Rights Act, passed in 1998 with cross-party support. What? The Tory manifesto, as I understood it, said we would remain signatories for at least the next five years. This leaderine is, as we know, not sturdy but capricious. Even so, this latest U-turn is her basest yet.

To be fair to her, she has often expressed reservations about the Human Rights Act, as have several other right-wingers. Believe it or not, two years ago, David Davis, Brexiteer-in-chief, came out strongly against Conservative plans to replace the Act with their own, home-cooked Bill of Rights. At the time, he was a conspicuous champion of guaranteed liberties and an ally of the then director of Liberty, Shami Chakrabarti.

Is that Mr Davis still with us? Or has he morphed into someone who totally repudiates his former self?

In 2013, Chris Grayling, when justice secretary, opined that "the ECHR did not make this country a better place". Well, say that to the Hillsborough families and campaigners who wanted and deserved truth and justice and had been fobbed off for years, in that very British way, by various authorities. They used Article 2 of the Human Rights Act, which places a duty on the state to properly investigate such serious cases.

And ask gay soldiers for their views. Servicemen on the mainland and in Northern Ireland went to court because they were institutionally discriminated against in the army. They got gay sex acts decriminalised and won equal rights at work.

Domestic violence victims have used this law to keep themselves and their kids safe. Graham Gaskin, when a child, was most dreadfully treated in the care system. British courts upheld the right of the local authority to keep much of this information confidential. He took his case to the European Court of Human Rights in Strasbourg, which decided his rights had been breached by the British government because the claimant had not been able to take his case to an independent appeal body. (This was in 1981, long before the Human Rights Act was passed in Britain). The European Council's Commissioner for Human Rights pushed to protect all children from corporal punishment.

Richard Driscoll was unable to walk and his wife was blind. They had lived together for 65 years, supporting each other. Then, in 2010, he had to go into a care home and both were traumatised. Thanks to the Human Rights Act, they got to live together once more. Prisoners, undeserving asylum seekers, and crooks have also had their rights upheld, much to the chagrin of right-wingers.

The Human Rights Act was even useful to Prince Charles and Camilla when they wanted to have a civil wedding. It helped them to bypass traditions and constitutional encumbrances. This law works for the poor, disabled, troubled, and the most privileged. Laws in good societies protect the good, bad, and the ugly.

We have all been disturbed by some court judgments. When paedophiles try to argue for their human rights, for example, it feels wrong and repugnant. It feels just as wrong when, say, a rape trial judge passes a lenient sentence for some incomprehensible reason. No laws or system can be perfect or totally fair.

But, on balance, the ECHR and our Human Rights Act have made this a better country and us better people. I used to think there was nothing wrong with smacking kids, because that is what happened to me. I learnt that was wrong. My children grew up into decent human beings without needing cruel chastisement.

The Tories will, I believe, win this election. Remember, though, it was Winston Churchill who helped draft the 1951 European Convention on Human Rights. Today conscientious, influential Tories such as Ken Clarke, Dominic Grieve, both QCs, staunchly defend the unprecedented protections the Human Rights Act and ECHR offer all citizens regardless of background.

Michael Mansfield, the radical barrister, who represented those wrongfully convicted of the IRA bombs in Guildford and Birmingham, rightly believes: "If the Human Rights Act were scrapped, people would soon realise how our daily lives have benefitted."

The power-hungry Mrs May is determined to crush our precious, now inviolable human rights. It is time for a left-right alliance to stop this act of political vandalism.