Some individuals and groups wanted the slave trade to continue - often they had a financial interest in slavery. Some owned plantations which depended upon slave labour while others profited from the trade of goods produced using slave labour.
It was not just rich planters or merchants who sought to defend the slave trade. Many ordinary British workers made a living from the industries which depended upon it, such as:
MPs - Some MPs were planters themselves or had business interests which made money out of slavery. The planter MPs were wealthy and powerful enough to bribe other MPs. They did this to get their support in blocking abolitionist bills passing through Parliament.
Merchants and workers - British cities which had grown rich on the profits of the slave trade were also keen to continue their success. Many people's jobs in ports such as Bristol and Liverpool depended on the business created by the slave trade.
In 1775 a petition was sent to Parliament by the mayor, merchants and people of Bristol in support of maintaining the slave trade.
African rulers - They played a key role in the slave trade and also tried to defend it. When the British abolished the slave trade in 1807, the King of Bonny in Nigeria wrote to Parliament to complain.