Thatcherism is known as the political and economic policies brought to light by Margaret Thatcher, who was the British prime minister between 1979 and 1990. Governments of people such as David Cameron and John Major continued to represent Thatcherism after Thatcher's resignation in 1990. The whole idea of Thatcherism consisted of the privatisation of nationalised industries and trade union legislation. On the other side however, classical liberal ideology was committed to individualism, equal rights, and liberty, and in order to achieve their aims, classical liberal ideologists believed that they needed a free economy that had as small as possible government interference.
Thatcherism as a ideology as a whole consists of the general theory that it is a possible platform that adheres free markets, as well as decreased tax and government spending. What can be seen as the main connection between Thatcherism and classical liberal ideology would be the movement of Margaret Thatcher herself, as she has commonly been described to have had a liberal movement within the conservative party. The borrowed aspects of this liberal movement in the conservative party of Thatcherism would be emphasis placed onto having a free market that included a reduced amount of government intervention, which can be closely connected to classical liberal ideology's idea of a minimal amount of government intervention. Real-world examples of Thatcherism's attempts on a free market would include its efforts of privatisation, which could be seen on the 1979 election manifesto, which then further privatised many industries such as British airways in 1987 to name one.
Thatcherism can be seen to borrow many aspects of Classical Liberal Ideology, as discussed above, however, it has only borrowed aspects, being an ideology of its own. Firstly, Thatcherism was considered a liberal movement that took place within the conservative party, meaning that it was not a full-fledged liberal movement, and was not considered to be level with Classical Liberal Ideology on many of its ideas. Some of these ideas included the fact that Thatcher during her reign as prime minister was considered by some to be authoritarian at times, meaning that she favoured strict obedience at the expense of personal freedom, whilst Classical Liberal Ideology promoted and supported a more gentle approach to the population, where they aimed to support the population whilst maintaining low levels of government intervention, something in which Thatcher didn't maintain, with some considering her administration to be iron-clad, with heavy amounts of intervention, despite her intensions of reducing government intervention. Thatcher also contradicted the ideas of classical liberal ideology by attempting to use government intervention to put an end to socialised welfare.
In conclusion, it can be deduced that Thatcherism had borrowed some key ideas from Classical Liberal Ideology, such as the emphasis both ideologies placed on minimal government intervention, and a free market, as well as Thatcherism being considered as a liberal movement, despite that movement only being within the restrictions of the conservative party. The extent of how much Thatcherism borrowed from classical liberal ideology however is challenged when the differences between the ideologies are compared, as discussed above, as despite their similar intensions, they went about attempting to achieve their goals in different ways, with Thatcher's supposed authoritarianism and large amounts of intervention causing controversy as she prided herself on reaching minimal government intervention. Furthermore her attempts to use government intervention to stop socialised welfare, was clearly against the theory of classical liberal ideology, that believed the population should be supported, socialised welfare included. Therefore, the extent of which Thatcherism borrowed from classical liberal ideology depends on the perspective and opinions of those making the judgement, however it is clear that Thatcherism did borrow a few key ideas from classical liberal ideology.