[citation needed] In 2017, Slutsky called the Catalan independence referendum a "litmus test" for the European Union, asking "Will Brussels agree with the right of nations to self-determination, as was convenient with Kosovo, or will it continue to insist on the principle of territorial integrity" as it did with Crimea.

[10] In October 2018, Slutsky expressed concern that United States plans to withdraw from the Intermediate-Range Nuclear Forces Treaty would result in a new Cold War and potentially an armed confrontation.

In response Slutsky compared himself to Harvey Weinstein, claimed to be the target for defamation and provocation and threatened TV Rain with legal actions.

[18][19] A number of parliamentarians spoke in defense of Slutsky including so-called State Duma "female club" (co-chairmen of different political factions: Yelena Serova, Olga Yepifanova, Tamara Pletnyova, Elena Strokova) and the Duma chairman Vyacheslav Volodin who linked the accusations to political motives.

[25][26] The same day the director of the Information and Press Department of the Ministry of Foreign Affairs of the Russian Federation, Maria Zakharova, also recalled the ambiguous behavior of Slutsky towards her.

[25][26] At the end of February, the journalists from State Duma press pool approached legislature's leaders with request to discuss the behavior of Leonid Slutsky.

[36][37][38] On 8 March 2018 Alexei Navalny and his Anti-Corruption Foundation (FBK) published an investigation about the property of Leonid Slutsky and accused the deputy of illegal wealth accumulation, as his family does not have an official business, and its total income is unlikely to afford the cars, with the two Bentleys costing about 30 million rubles).

[37][39] The investigation of Alexei Navalny and his the FBK states that in the period from June 2017 and March 2018, a Mercedes-Maybach S500 owned by Slutsky violated traffic rules 825 times (including driving on the oncoming lane).

[40] In January 2017, developer Sergei Polonsky appealed to Prosecutor General of Russia Yury Chaika with a demand to file criminal charges against State Duma deputies Vladimir Resin and Leonid Slutsky.

His role included peace talks and negotiations on the wounded Ukrainian soldiers in the Azovstal steelworks following the end of the Siege of Mariupol.

[49][50] In March 2018, journalist Anna Mongait reported that singer Zara advanced her political career and received the title of "Honored Artist of the Russian Federation" because of her relationship with Slutsky.

On 11 June 2011, the day of Orthodox holiday of Pentecost, Slutsky landed on the territory of Trinity Lavra of St. Sergius on a helicopter, without having warned anyone in advance.

[52] According to the deputy, he hurried to meet with Patriarch Kirill of Moscow, but because of traffic jams on the Yaroslavl highway he had to use the services of a helicopter company.

Its Saratov department was involved in fraud with land and, among other things, it got a lease on a pond, where, according to the documents, it planned to build a children's car-racing track.