UK Conservative party posters would return to this format for their next eighteen years in government and beyond, with numerous parodies also made. Heavily discussed in books also (e.g. here, here and here).
Despite the iconic impact of the full-size poster, it originally only ran in twenty locations, so in fact most people would have seen a smaller-size version or a reproduction in a newspaper. (The ad was actually not directly created for an election campaign: it ran in 1978 to try to intimidate the Labour party in what was presumed to be the run-up to a 1978 election. But the election that placed Thatcher in power did not come until the following year.)