About 200 protesters linked to the camp against \"corporate greed\" outside St Paul\'s Cathedral have entered Parliament Square. Some 1,000 Occupy London Stock Exchange (OLSX) protesters had earlier set off to march to Trafalgar Square, but a breakaway group headed instead for the area outside the Houses of Parliament. The Met Police says any protest is \"illegal\" without prior agreement. The BBC understands the OLSX demonstrators have now agreed to leave. Police had earlier cordoned off Parliament Square to prevent the demonstrators from entering, but several hundred made it through a police barricade. There was a confrontation at the top of Whitehall as the group tried to get through a police line, the BBC\'s Ben Ando reported from Parliament Square. A line of police is at the square keeping the protesters, some wearing the Guy Fawkes masks that have become a symbol of their protest, in an area outside the Houses of Parliament. No arrests A Met Police spokesman said it was an illegal protest because demonstrators were \"not allowed to be in certain areas of Parliament without prior agreement\". He said police were negotiating with the demonstrators to leave - but the BBC understands they have now said they will clear the area. There were no arrests, police said. Earlier, the former canon chancellor of St Paul\'s Cathedral - which protesters have been camped outside for three weeks - said the Church of England needed to highlight the human cost of financial injustice. But the Reverend Dr Giles Fraser, who resigned from his post at the cathedral last month over its handling of the Occupy protest, said he was not sure the Church should get too involved in \"proposing specific answers to complex economic problems\". \'Financial injustice\' On BBC Radio 4\'s Thought for the Day on Saturday, he said: \"St Paul\'s Cathedral is built on a deep theological fault line. On the one hand it\'s set within the boiler room of global capitalism, and on the other it proclaims a theological story that has some pretty fierce things to say about money and wealth. \"These two powerful tectonic plates, God and mammon, meet right under Wren\'s magnificent baroque masterpiece. \"It\'s little wonder that St Paul\'s can be one of the most challenging and uncomfortable places in which to do theology.\" He spoke of \"the calling of the Church to draw attention to the human cost of financial injustice\". \"This has nothing to do with bringing down capitalism. Markets create wealth and jobs, and indeed those who want to dispense with capitalism are often better at saying what they\'re against than they are at proposing convincing alternatives. \"Nonetheless, part of the reason why Christianity is so suspicious of money is that the power and glamour of money can easily corral us into a narrower and narrower sense of what it is to be human,\" he said.