When the Holy Spirit hit St Paul's Onslow Square, SW7, on Sunday morning, I felt it through the floor. There were four heavy thuds as congregants fainted, and then sudden rapid drummings - like the noise that rabbits make to warn one another - when people started to shake uncontrollably and beat their feet against the floor.

Towards the front a woman with short black hair was bouncing like a road mender's drill for about 20 minutes. Sometimes she laughed but mostly she just bounced against the hands that were laid on her from the sides. From somewhere came tremendous pantings and gaspings which were not quite sexual.

The laughter was really strange. From three or four places in the church you could hear this gut-busting abandoned giggle. It was not an adult sound at all. It was more like the laughter that you get by tickling a happy toddler; but it was coming from respectable women in their thirties. They sounded as if they had just been told the best joke in the world and it was going on and on and on. . .

Up at the front, the Rev Nicky Lee was gesturing around the congregation with an arm straight out, palm raised. He prayed into a microphone in calm, well-modulated tones. 'Those who want to be prayed for, please come to the front, Others, if you want tea or coffee, at the back, are welcome too.

In front of me a tanned blonde in a blue dress, who had been prayed over for about 10 minutes, suddenly went down sideways across a line of plastic chairs. She was helped to the floor, where she wept with heart-rending abandon. A single string of pearls showed in her newly washed hair. She curled on her side and sobbed while two women helpers knelt beside her with their hands on her back, praying quietly.

Slowly her weeping died away. There was another burst of drumming on the floor, but this was just a rush of children released from the creche part of the service. They ran down the side of the church, apparently taking no notice of what was going on and rejoined their parents at the back. This was, after all, an Anglican church in the heart of South Kensington, with a well-heeled congregation that had put nearly pounds 4,000 into the collection bag the previous Sunday for Rwandan relief. If people were going to faint, shake and laugh like drunks, this was no excuse for staring.

None the less, the scenes at St Paul's and a number of other London churches over the past three weeks have led enthusiasts to believe that a real religious revival is under way.

'I believe we are in a season when God is refreshing his church, Mr Lee told the congregation. 'He is pouring out his spirit.

'Whenever we have gathered, we have seen God coming with refreshing streams of spirit. Last Monday, at the open meeting, there were people lying on the carpet, people crying as God was touching them; six just roaring with laughter, rolling on the floor over and over, holding their sides as if they would really burst.

'Some of them simply could not walk for laughter. These are sensible, normal people. This brought a laugh: a social, in-group laugh, not like what was to follow.

The phenomena started apparently in Toronto, at a small evangelical church called the Airport Vineyard Fellowship. They have spread, said Mr Lee, 'like the Beijing flu, by contact from person to person. It was brought to London by Sandy Millar, the vicar of Holy Trinity, Brompton.

HTB, as it is always known, is the largest evangelical Anglican church in London, the cathedral of the 'happy clappies. At HTB they believe in rugger and the Holy Spirit, not in that order. They are clean-cut, energetic and enormously successful.

The rest of the Church of England regards them with a dislike it finds hard to explain, but an anecdote might help to explain it:

When I left St Paul's, I went to lunch with a curate in the East End whose wife had been taken to HTB once for a service. After they left, the group she was with stood on the Brompton Road, waiting for a bus. None came. They decided to pray for one. They stood on the pavement praying for some time. They were enjoying themselves so much that none of them noticed when a bus actually appeared, and passed them without stopping because they did not seem to be interested.

St Paul's is one of HTB's most celebrated successes. The building stood derelict for seven years before being taken over by a group of volunteers who have now turned it into a prosperous and self-sustaining church. Although Mr Lee is still technically a curate at HTB, in practice he is the vicar of his own, thriving church.

The Sunday morning Family service began with half an hour of 'worship songs, from the Jive Bunny hymnal, led by a rock band. The congregation stood and sang and clapped through all this, many with their hands waving imploringly in the air like lightning rods to attract the Holy Spirit.

After that came notices, including an appeal that was almost an instruction from Silla Lee, Nicky's wife, for people to go on a family Christian holiday: 'Every day for a whole week, you can go to worship, seminars, sessions; you can even lie around in the sun.

When Mr Lee spoke it was not like a traditional sermon: he was cogent, well-modulated and practical. He read from the diaries of George Whitefield, an 18th century evangelist, contemporary and friend of John Wesley - he, too, had had experiences similar to those being played out in London now. He had collapsed while preaching, 'slain in the spirit, just as Mr Lee had done the previous Monday evening.

Then he talked about Pentecost, the pattern for all these experiences, when the Apostles started to talk all the languages of the world and 'everyone was amazed and unable to explain it; they asked one another what it allmeant. Some, however, laughed it off. 'They have been drinking too much new wine,' they said'.

Mr Lee told them he had believed this before, but never understood it until he had seen the laughter fits

falling on the congregation. Some evenings people had had to be helped from the church, they were laughing so hard. He was sure a policeman would have taken them for drunk.

He read from cards which members of the congregation had filled in, describing their experiences. 'I was overcome with shakes, and my whole body tingled all over.

'I was on the floor for about two hours, and could not walk properly the next day. The peace and joy of God's love was running through me like electricity.

'Those of you who have not yet experienced anything particular yourselves should go on seeking God and asking for him. Sometimes the Lord withholds his hands because he waits until we are even more thirsty, and even more hungry for him.

All this is said in the most unhysterical, SW7-ish way imaginable. There is nothing of the hucksterish atmosphere of a Morris Cerullo or Reinhard Bonnke rally. And then, in silence broken by the rustle of prayer, the bodies start thudding against the floor.

Mr Lee believes that the point of all this is to make the beneficiaries love God more, and more deeply rather than to startle the outside world. 'This sort of ministry should become more and more part of the regular ministry of the church, he said. 'I hope that it will go on and on until the Lord returns. (Photograph omitted)