[1] He belonged to the reformist wing of the governing Socialist Unity Party of Germany at the time of the pro-democracy transition inspired by then Soviet leader Mikhail Gorbachev.

In 1971 he became a licensed attorney, and during the 1970s and 1980s defended several prominent dissidents, including Rudolf Bahro, Robert Havemann, Ulrike Poppe, and Bärbel Bohley.

In addition to his legal work, Gysi emerged as one of East Germany's leading Gorbachev-inspired political reformists within the SED, especially towards the end of the 1980s.

In 1989, he and a group of lawyers presented a counter-draft to the government's Travel Bill, which authorised mass public demonstrations.

This led to a mass rally on East-Berlin's Alexanderplatz on 4 November[6] in which he spoke and called for reforms, including free elections.

In December 1989, he became a member of a special SED party session investigating official corruption and abuse of power.

In 1992, it was alleged Gysi was an informer (Inoffizieller Mitarbeiter, IM) of East Germany's Ministry for State Security (the Stasi).

In 1998, the Bundestag's immunity committee concluded that Gysi had been a collaborator with the Stasi from 1978 to 1989 under the name IM Notar, and fined him 8,000 Deutsche Mark.

[citation needed] In 2000, he resigned as chairman of the PDS's parliamentary group, but continued as an active member of the party.

He emphasised practical issues and advocated the reinstitution of some of what he sees as the better aspects of East Germany's system, such as extended child-care hours and a longer school day.

After a scandal involving his use of airline "bonus miles" he had acquired on trips as a Bundestag member, he resigned on 31 July 2002 from the Berlin city government.

Gysi remained the PDS's undisputed front man in many people's minds and continued to appear in public.

In 2014, Gysi wrote his analysis on the contemporary Ukraine crisis in the Israel Journal of Foreign Affairs, where he described similarities between the United States and Russia in their transgressions of international law.

While the Left came up short of the five percent electoral threshold, his win, together with those of Gesine Lötzsch in Berlin-Lichtenberg and Sören Pellmann in Leipzig II, qualified the party for list seats proportional to its vote.

[13] In November 2014, after being invited by Inge Höger and Annette Groth, also members of The Left (Die Linke) to talk with them in the Bundestag, journalists Max Blumenthal and David Sheen learned that Gysi tried to cancel the meetings on the grounds that Blumenthal and Sheen held radical views[14][15] from which he wished to dissociate the party.