In the 1980s and 1990s, there was a divide between the moderate Bern wing and the new Conservative right-wing Zürich wing.<ref>Skenderovic, pp. 129.</ref> However, mostly in the 1990s, the conservative faction took control of the national party.<ref>Skenderovic, pp. 132-135, 141.</ref> During the same period, the SVP grew dramatically in size, making large increases in its budget and expanding its representation and reach to all 26 cantons.<ref>Skenderovic, pp. 133, 142.</ref>
Arguably the most important action of the SVP was its successful opposition of Swiss entry into the European Economic Area (EEA) in 1992. As a strong conservative, Blocher strongly opposed Swiss integration with, and thus a loss of sovereignty to, outside powers, and he was able to convince the national party to adopt his position.<ref name="pp.135">Skenderovic, pp. 135.</ref> The SVP was one of only two major parties to oppose membership, the other being the [[leftist]] Greens.<ref name="Trampusch">Trampusch, Christine and André Mach (2011). [https://books.google.com/books?id=5nOrAgAAQBAJ&pg=PT63&lpg=PT63&dq=Swiss+People's+Party+%2B+EEA+1992&source=bl&ots=6ykAlPUxDf&sig=KnL0LwEuLNklUYfTL_lQWFuobHI&hl=en&sa=X&ved=0ahUKEwj56sX01NvPAhVI7SYKHdgJC-0Q6AEIPjAG#v=onepage&q=Swiss%20People's%20Party%20%2B%20EEA%201992&f=false Switzerland in Europe: Continuity and Change in the Swiss Political Economy]. Routledge. ISBN: 978-0-415-58051-9.</ref> The referendum to join the EEA failed, a major success for Blocher and the SVP, and a majority of SVP members voted with Blocher, strengthening his position in the party.<ref name="pp.135"/> The vote has been considered "a turning point" for the SVP and Swiss politics in general.<ref>Skenderovic, Damir (January 21, 2013). [http://policy-network.net/pno_detail.aspx?ID=4317 The SVP: A success story of right-wing populism]. ''policy-network.net''. Retrieved October 14, 2016.</ref> Since then, opposition to European integration and loss of national sovereignty has been "a main issue" for the SVP, and in the coming years it sponsored several other conservative national initiatives, which usually were not successful.<ref>Skenderovic, pp. 135-138.</ref>
The SVP and its predecessors had "showed remarkable stability" in "electoral support" until the 1990s.<ref>Skenderovic, pp. 127.</ref> However, the SVP grew dramatically in size, becoming the largest party by 1999 with 22.5 percent of the vote.<ref>[http://www.politik-stat.ch/nrw1999CH_de.html 1999 federal election results]. ''politik-stat.ch''. Retrieved October 12, 2016.</ref> The SVP continued to increase in the 2003 and 2007 elections.<ref name="2003 results">[http://www.politik-stat.ch/nrw2003CH_de.html 2003 federal election results]. ''politik-stat.ch''. Retrieved October 12, 2016.</ref><ref>[http://www.politik-stat.ch/nrw2007CH_de.html 2007 federal election results]. ''politik-stat.ch''. Retrieved October 12, 2016.</ref>