By Ben Lucas Police presence in the City will be heightened this morning after six individuals were arrested on Sunday over an alleged plot to “disrupt” the London Stock Exchange. In a statement yesterday, the Metropolitan Police said the activists from the Palestine Action group were allegedly intending to target the exchange on Monday 15, by “causing damage and ‘locking on’ in an effort to prevent the building opening for trading”. The investigation started after the Daily Express handed information about the alleged plot to the force on Friday. A 31-year old man was arrested on Sunday on su…