In June 2021 the United States Department of the Treasury designated Peevski, the public official Ilko Zhelyazkov and the Bulgarian oligarch Vasil Bozhkov, along with 64 entities owned and controlled by Bozhkov and Peevski, for their roles in public corruption, pursuant to Executive Order 13818, which builds upon and implements the Global Magnitsky Human Rights Accountability Act.

[13] Since these sanctions, Peevski has worked closely with representatives of Ukraine to reduce Russia's influence in the energy sector in an attempt to launder his way out of the Magnitsky Act.

[21][22] In mid June 2014, three people were arrested due to their involvement in an alleged murder plot against Peevski, but they were eventually released because of a lack of sufficient evidence.

[26] In 2023 and 2024, Peevski repeatedly accused the government of unnecessarily prolonging the imports of Russian oil in Bulgaria, instead of banning them in line with other EU countries.

[30] Those were second amendments, filed by Peevski and his colleagues from the Parliamentary group of MRF, with reference to the so-called "KTB case" and unveiling the truth about the embezzlement of the bank by its majority shareholder Tzvetan Vassilev.

In 2016 the MP together with two more members of the same parliamentary group - Yordan Tzonev and the former minister of finances Peter Chobanov, moved urgent amendment to the Bank Insolvency Act in order to allow the publicizing of the report of AlixPartners Services UK LLP, which was contracted to trace and take action for the preservation and recovery of the assets of the failed Corporate Commercial Bank (KTB), Bulgarian News Agency reported.

According to the document, the audit confirmed that the bank functioned as a financial pyramid and was siphoned off through large loans to companies related to the majority shareholder Tzvetan Vassilev.

Yet, the opponents of the amendments stated that the bill attacks Delyan Peevski's rivals because it requires disclosure of all sources of financing of media organizations other than the proceeds from advertising and bank loans.

The day after bill's approval, Peevski, Hamid, Tzonev and Krusteva moved additional amendments requiring disclosure of bank loans and advertising incomes as well in order to meet the expectations of society.

[35] The legislative efforts of the MP within the 49th National Assembly are focused mainly on the judicial reform, Bulgaria's support for Ukraine and enforcement of the EU sanctions against Russia.

[36] The draft law was submitted by members of the parliamentary groups of "We Continue the Change-Democratic Bulgaria", GERB-UDF and the opposition Movement for Rights and Freedoms (MRF).

The draft legislation sets up a mechanism for the implementation of Regulation (EU) 2019/452 of the European Parliament and of the Council of 19 March 2019 establishing a framework for the screening of foreign direct investments into the Union.

[38] Furthermore, Peevski was among the MPs who signed and filed a bill, allowing the state to terminate the concession of the Port of Rosenetz, held by the Russian owned company Lukoil Neftohim.

[39] He also filed along with other MPs from MRF, GERB and PP-DB a second bill, which aims to end the derogation from the EU sanctions, allowing Bulgaria to continue importing Russian crude oil.

[40][41] Peevski has criticised PPDB for their decision to not support the immediate cessation of the derogation of the Rosenets Refinery to Lukoil in October and November 2023, even going as far as to characterise them as "Pro-Putin" parties.

[46] On the 30th of November, during a debate about the appointment of the Vice-Chief of the National Health Insurance Fund, Peevski and PP co-leader Kiril Petkov engaged in an aggressive argument at the front-bench, which allegedly included the use of vulgar language.

[48] Peevski voted in favour of the proposed Constitutional Amendments in all their readings, stating upon the conclusion of the process on December 22, 2023, that Bulgaria has now "truly become a parliamentary republic" in reference to the decreased powers of the presidency.

[50][51] On the 7th of November, after a period of public absence, DPS Chairman Mustafa Karadaya announced his intention to resign, leaving Honorary President Ahmed Dogan the Acting Leader.

During an emergency meeting of the Central Council of DPS on the 17th of November, chaired by Peevski, he officially announced his intention to run for the position of chairman of the party.

[56] On the 26th of November, Peevski attended a conference of the DPS Youth Wing, and gave a short speech in which he promised to support and coordinate with them if he was to be elected chairman.

[62] On the 30th of January, 2024, Peevski, together with Chakarov, met the foreign minister of Turkey, Hakan Fidan, which was seen as a sign of approval of the new DPS leadership by the Turkish government.

"In August 2021 it was reported that Delyan Peevski has filed a request before the US Treasury Department's Office of Foreign Assets Control (OFAC) to remove the sanctions.