FEW who were around in the 1960s and 1970s during the period of the Vietnam war will ever forget the savage images of Lyndon Baines Johnson and Richard Nixon drawn by Gerald Scarfe, one of the finest contemporary political cartoonists.

But, closer to home, he found his perfect subject in Margaret Thatcher. Pretentiously regal, monstrously callous — and more than slightly deranged — she was already a living caricature of inhumane coldness and vicious narrow-mindedness before being graphically lampooned by Scarfe.

This he did with wit, insight and skill, producing gleefully unhinged and grotesque images which exposed her strange and unpleasant character. In the process he transformed her into a mad cow, a dominatrix, a reptile, the Union Jack, the front of an aircraft carrier, a pterodactyl and a mangy show dog — to name but a few.

“I didn’t agree with her values, but she was amazing material,” Scarfe had said. “I could turn her into anything acerbic or cutting, like a dagger or a knife, probing and vicious.”

He indeed used his pen like a knife, carving sweeping, violently pointed and bizarrely angular lines with deliberately offensive satirical intent. Using both black ink and colour washes, he drew her again and again with graphic rancour as a beak-nosed, blood-fanged monstrosity.

The large cartoons in this exhibition show him bringing the same savage and frightening intensity to his satirical art as his subject brought to her brand of brutal, uncaring “conviction politics.” But Scarfe had a more moral, as well as humorous, purpose because it is the search for truth that powers Scarfe’s art.

Looking at these striking images, you sense the outrage that drove him to peel back Thatcher’s hypocritical mask and expose the obscene aggression, violence, greed and class hatred that threw millions of people onto the dole, destroyed mining communities, deregulated the City, strangled public spending, introduced the poll tax and generally did far more than any other modern prime minister to shatter a society that she didn’t think existed in the first place.

Some of the finer points of internal Tory Party treacheries in the eighties lampooned by Scarfe may be lost on a younger public and it’s a pity that there are no cartoons in the exhibition about the 1984 miners’ strike.

But as the general election looms — and at a time when the country is still divided between those who think Thatcher saved the nation and those who believe she nearly ruined it — these highly entertaining cartoons are not only artistically brilliant but still have a major political value.

Runs until June 7, box office: thebowesmuseum.org.uk