Many said that union would lead to an increased burden of taxation. This was accepted by union supporters, as in England people paid higher taxes than in Scotland.
One of the results of English domination of a British Parliament might be favour given to English trading interests, such as had occurred over the Darien Scheme. Town and Burgh Councils voiced concerns about the loss of Royal Burgh rights if union took place, with fears that English merchants would come north and dominate Scottish markets.
Councillors also feared a threat to manufacturing posed by English producers of better-quality and lower-priced goods.
English interests would dominate all aspects of trade - English currency, weights and measures would be used in Scotland, and Europe would favour English trade over Scots.
Many Scottish MPs feared that their voices would be lost in a British Parliament due to lack of Scottish representation. The Treaty proposals suggested that Scotland would have 45 MPs while England would have 513 and in the House of Lords there would be seats for only 16 Scottish peers.
Fears over the standing of Parliament were raised by those who felt that the Scottish tradition of MPs standing up to the monarch would disappear.
Jacobites also feared union, since it would confirm the Hanoverian succession in Scotland and end the possibility of a return of the Stuarts to the throne.
Some MPs argued that union meant the sacrifice of Scotland’s reputation in Europe. There was a common belief that Scotland would become “Scotlandshire”, as if it was a part of England.
Many university professors and lawyers protested at what they saw to be threats to Scottish legal and educational traditions.
Episcopalians, particularly in the North-east, feared that a British monarchy would always favour a Presbyterian Church in Scotland.
Despite union guaranteeing a Presbyterian Scottish Church, some feared future domination by the Church of England, leading to the return of bishops to the Church of Scotland.