The Royalist party in Parliament was mainly built around a strong anti-Scottish sentiment. Many resented the Covenanters' religious vision that meant imposing their Presbyterianism across the British Isles. At Westminster, the Scots' Presbyterian demands aroused both national and religious hostility to any form of union with the Scottish church. The Royalist party was an anti-Scottish party before it was a Royalist party. More Royalists hated the Scots than loved Charles. Just as the Scots resented English dominance of their church, so the English would not put up with Scottish interference.
As the Long Parliament continued to sit, the religious rhetoric cranked up. In December 1640, a 1,500 strong mob delivered a petition to Parliament demanding the 'Root and Branch' reform of the Church and abolition of bishops.
The preachers at the periodic fasts, or days of prayer and preaching called by Parliament, inspired MPs with lurid readings from the Book of Revelations and Old Testament prophecies of damnation with the Pope cast as the seven-tongued Whore of Babylon. Mobs circled the Lords attacking bishops; across the country iconoclasm erupted against 'Papist' monuments and images. Again and again, the Commons returned to the issue of religion which polarised its members into Cavaliers or Roundheads.
The Royalists were not necessarily passionate defenders of Charles but they were passionate in their defence of a church which appeared to be under attack from Puritan extremists. But the Parliamentarians were adamant in their belief that England was being subjected to the forces of the Antichrist. They were convinced that Charles was the victim of a Popish plot; that evil, Catholic counsellors had somehow indoctrinated their King against the country. They needed to save him.