"John Ramsay?" A murmur of despair went round the Kent audience attending an Amazing Grace preview.

Perhaps the researcher who renamed Teston's Rev James Ramsay could stand up and be counted.

The county didn't do much better when the cameras focused on the historic pact made by MP William Wilberforce and his friend Prime Minister William Pitt, seated under an ancient oak tree at Keston, near Bromley , to bring the abolition bill before Parliament in 1788. Instead, the scene was played out on a golf course. Have you ever tried playing golf at Keston Ponds?

Ok, ok, let's honour the theme of humanity - director Michael Apted and his crew are forgiven - Amazing Grace is this year's must-see film.

It charts the story of the young MP William Wilberforce who became one of the most celebrated men in 19th century England for his remarkable campaign against the slave trade.

Ioan Gruffuud puts in a powerful performance, particularly during noisy scenes filmed inside The Royal Chatham Historic Dockyard Church, which was converted as the interior of the House of Commons. Many local people were extras and their presence did not go unnoticed by Gruffuud, who admitted: "It was very daunting to be confronted, suddenly, with the set full of extras playing Members of Parliament".

Gruffuud's other challenge was to sing Amazing Grace in 'the Gentleman's Club' , to show his peers exactly what he stood for. It's an arresting scene. Wilberforce, despite his small frame, had a towering presence and an incredible voice, but Gruffuud carries it off. " Luckily, I had my singing teacher from drama college, who I hadn't seen for 10 years, to guide me," he said.

The hymn Amazing Grace was written by John Newton, played by Albert Finney, an ex-slave ship captain who suffered a crisis of conscience and turned to God. Newton was Wilberforce's childhood vicar and became his mentor when Wilberforce struggled with the personal conflict of being a devout Christian and an MP.

Here's an idea. Let every child, in every school, sing the hymn this week to mark the 200th year of the abolition of the slave trade. Put the film on the National Curriculum so no one forgets the atrocities that were suffered and, importantly, remember that almost one million humans are still trafficked across the world.

Amazing Grace brings home that Wilberforce's pioneering strength and resilience is still needed today; he was left frail by his years of campaigning and died just before the passing of the Slavery Abolition Act of 1833 (which ensured the emancipation of all slaves) - some 26 years on from the original 1807 abolition act.