He is a member and the Division Chief of Putrajaya of the United Malays National Organisation (UMNO), a component party of the BN coalition.

He was dropped from the cabinet following the March 2008 general election, where the ruling Barisan Nasional coalition received a serious drubbing at the polls.

After his victory for third time in 2013 general election, Adnan has returned to the cabinet and appointed Minister of the Federal Territories.

However, he lost his cabinet post as BN was relegated to opposition while the federal government was taken over by Pakatan Harapan (PH).

23 witnesses called including Chai and former Kuala Lumpur City Hall mayors, Ahmad Phesal Talib and Mohd Amin Nordin.

[2] On 17 July 2019, Chai took out RM2 million receipt from his wallet which he said is evidence of payment by Umno, to show the sum is for political donation.

[2] On 21 December 2020, Judge Mohamed Zaini Mazlan said defence failed to challenge evidence brought by the prosecution.

Tengku Adnan's counsel is arguing that the judge was wrong in not accepting Chai's testimony and that the receipt issued to the businessman for the funds shows that the payment was a political donation.

The formation of the commission was a follow-up to a recommendation by a three-man panel which was tasked to determine the authenticity of a video clip of a telephone conversation that raised the allegation.

Following the findings of the Royal Commission, the Malaysian cabinet ordered the Attorney-General to immediately direct agencies to investigate the allegations levelled against six prominent individuals identified in the Lingam video clip affair.

From my understanding, out of 10,000 unemployed bloggers, 8,000 are women.In 2017 Tengku Adnan participated in a radio interview in which he discussed his plan to expand the federal territories to include Penang, Langkawi and parts of Malacca.

[11][12] On 24 July 2019, the government had filed a lawsuit through the Inland Revenue Board (IRB), against Adnan to claim RM57.17 million in unpaid taxes since 2012 till 2017.