When Harold Wilson campaigned in 1970, a very young Conservative flung an egg which broke against him. Wilson showed humour and decency by shouting, "Don't touch that boy! Let him go! He should be bowling for England!"

In 2010 David Cameron's government removed funds from youth centres, thus closing one in Cameron's constituency where a 12–year-old boy met his friends. On the internet the boy invited other youths to picket the prime minister's constituency office, thereby using modern technology to promote a local democratic protest. Police went to the boy's school, took him from his class, and in the presence of a teacher (not his parents) told him that if public disorder happened outside Cameron's office he would be arrested, even if not present. He was told that armed police would be present, and hold him responsible if this led to physical injuries.

The UK is coming to resemble the USSR, treating citizens as potential enemies unless wholly obedient to the nations' bosses. That the police carry guns; may stop and search anyone without a warrant, and sometimes without reason; that people can be sentenced for crimes without corroborating witnesses; that folk are invited to spy on their neighbours and inform the police without being identified in court, are a few of the signs that the UK is going bad.

I once thought Britain a safe place, being born in 1934 and living on one of the best planned of Glasgow housing estates. Riddrie had nearly every social amenity, unlike later estates built without most of them. Riddrie gave me the lifelong illusion of belonging to Britain's middle class, as all our neighbours were fully employed between two world wars. My father had a small government pension for a wound received in the first war, supplementing his wage as a factory worker. His hobby was being unpaid secretary for such semi-socialist organisations as the Scottish Youth Hostel Association. This got him work as manager of a hostel for munition workers from 1940-45.

He never had such a well-paid job again, but my health and excellent further education were provided by our welfare state, which the war created. "The only good government is a bad one in a hell of a fright," said the hero of Joyce Cary's best novel, The Horse's Mouth. After the Wall Street crash and a worldwide trade depression, from 1931 Britain had been ruled by a mainly rightwing coalition. It led Britain into the second world war by appeasing Mussolini, Hitler and Franco, but on finding itself the only government fighting fascism in Europe, it rapidly nationalised all Britain. Through agreement with banks and trade unions it controlled industries, and froze profits, prices and wages. Despite severe rationing, British children who grew up during the war were healthier at the end than they had been since public health records began around 1900. Children in other lands did worse.

So the 1945 general election overwhelmingly voted for a Labour government that promised to keep Britain nationalised. Being Labour supporters, my father and I naively believed Britain had achieved a peaceful, democratic socialist revolution, unlike the USSR – an undemocratic police state – and better than the US, which was ruled by millionaires. But our government had acquired coalmines, railways and other industries through buying company shares at a high price from owners glad to sell them. The shares were no longer profitable. And nearly everyone running our nationalised industries belonged to the same rich class as their former owners. That is why Margaret Thatcher's denationalisations went so smoothly.

I began voting Scottish Nationalist in the 1970s, on seeing that, even with a Labour government, the English part of the UK was not going to promote social welfare by publicly owning the nation's oil. I hoped self-government would win for Scotland the level of social liberty, equality and fraternity enjoyed by Norway. A referendum held in 1979 showed 51.6% of Scots wanted that too; 48.4% did not. This followed a campaign where leaders of the Tory and Labour parties united to announce that a Scots parliament would cause a huge withdrawal of capital, resulting in the loss of Scotland's major industries. But the Labour party in Westminster had decided that those who chose not to vote would be counted with those who voted against, so the winners of the race lost it. Then the threatened withdrawal of capital and loss of industry happened anyway.

A devolved parliament became Tony Blair's gift to Scotland in 1999, when another referendum showed a bigger majority wanted one. When Lady Thatcher was asked what she thought her greatest achievement was, she replied, "Tony Blair and New Labour". Exactly. Like US citizens, the UK electorate has no chance of voting for a party which will do anything to seriously tax our enlarged millionaire class that controls Westminster.

If a yes victory in the September referendum gives Scotland an independent parliament with its own taxation powers, maybe Alex Salmond will start using them to equalise social benefits. Perhaps. I am disgusted by his support of Kenny MacAskill, the justice minister who is bringing Scots' law into line with England's.

The next Scottish election will be in 2016. I hope it will return a separate parliament of MSPs with independent minds who do not represent big business. May they thoroughly and publicly debate important measures, and vote upon them without regard to former party allegiances. That should let us try to do better. There is no chance of a better Scotland ruled from London. That is why many English who have come to live here will vote yes at the referendum.

• Alasdair Gray's new book Independence: An Argument for Home Rule is out now, published by Canongate