Wałęsa nominated Kaczyński to be the Security Minister in the Presidential Chancellery but fired him in 1992 due to a conflict concerning Jan Olszewski's government.

In 2001, Kaczyński co-founded the Law and Justice party, after splitting from the Solidarity Electoral Action and the Christian National Union, along with his brother.

[3] On 10 April 2010, Lech Kaczyński died, along with his wife, in the crash of a Polish Air Force jet that occurred on a landing attempt at Smolensk North Airport in Russia.

He was, however, supported by the electoral committee Center Civic Alliance, closely related but not identical to the political party Centre Agreement (Porozumienie Centrum) led by his brother.

Wałęsa nominated Kaczyński to be the Security Minister in the Presidential Chancellery but fired him in 1992 due to a conflict concerning Jan Olszewski's government.

[10] Kaczyński was the President of the Supreme Chamber of Control (Najwyższa Izba Kontroli, NIK) from February 1992 to May 1995[11] and later Minister of Justice and Attorney General in Jerzy Buzek's government from June 2000 until his dismissal in July 2001.

[12] In 2001 he founded the political party Law and Justice (Prawo i Sprawiedliwość – PiS), usually labelled 'conservative' by media, with his brother Jarosław.

He strongly supported the construction of the Warsaw Uprising Museum and in 2004 appointed a historical panel to estimate material losses that were inflicted upon the city by the Germans in the Second World War (an estimated 85% of the city was destroyed in the Warsaw Uprising) as a direct response to heightened claims coming from German expellees from Poland.

He also supported the construction of the Museum of the History of Polish Jews in Warsaw and was one of the signatories of the agreement to finance the project using the city funds.

In his first public speech as president-elect, Kaczyński said that his presidency would pursue the task of ameliorating the Republic, a process which he said would consist of "purging various pathologies from our life, most prominently crime [...], particularly criminal corruption – that entire, great rush to obtain unjust enrichment, a rush that is poisoning society, [and preventing the state from ensuring] elementary social security, health security, basic conditions for the development of the family [and] the security of commerce and the basic conditions for economic development.

In foreign policy, Kaczyński noted that many of Poland's problems were related to the lack of energy security and this issue would have to be resolved to protect Polish interests.

Aside from those issues, his immediate goals were to develop a tangible strategic partnership with Ukraine and greater co-operation with the Baltic states, Azerbaijan and Georgia.

[30] In November 2006 in Helsinki, at a European Union-Russia meeting, Poland vetoed the launch of EU-Russia partnership talks due to a Russian ban on Polish meat and plant products imports.

[31] As a reaction to claims by a German exile group Preussische Treuhand, which represents post-1945 German expellees from Eastern Europe, the Polish Foreign Minister Fotyga mistakenly threatened to reopen a 1990 Treaty fixing the Oder and Neisse rivers as the border between the two countries instead of the Neighborhood Treaty signed in the same year.

[32][33] Following the military conflict between Russia and Georgia in 2008, Kaczyński provided the website of the President of Poland for dissemination of information for blocked by the Russian Federation Georgian internet portals.

[37] On 10 April 2010, a Tupolev Tu-154M plane was carrying Lech Kaczyński, his wife Maria Kaczyńska, and other members of a Polish delegation (top public and military figures) from Warsaw to commemorate the Katyn massacre.

[42] On 11 April 2010, President Kaczyński's body was returned to Poland,[43] where he and his wife lay in state at the Presidential Palace in Warsaw.

After a Roman Catholic Mass at St. Mary's Basilica,[45] the presidential couple were laid to rest in a coffin, which was placed in the antechamber of the Crypt Under the Tower of Silver Bells beneath the Wawel Cathedral.

[46][47][48] A significant number of foreign dignitaries were unable to attend the funeral as a result of air travel disruption in Europe following the eruption of the Eyjafjallajökull volcano in Iceland.

[49] In June 2016, the Polish government announced it would re-open the investigation into the Smolensk jet crash with plans to exhume and autopsy all 96 of the victims.