The Election Commission reduced Tamang's disqualification period to 13 months, which ended on September 10, thus enabling him to contest polls. Tamang, who had earlier spent a year in jail after being convicted in a corruption case, had also been barred from contesting elections for six years.
Tamang was found guilty in 2016 of misappropriating government funds in a cow distribution scheme when he was the Minister for Animal Husbandry in the 1990s. The verdict was upheld by the state high court as well as the Supreme Court.
He had moved the Election Commission to waive his disqualification period.
The Congress also questioned the government on "what is this new very-very cheap definition of pure politics" for commuting the death sentence of Balwant Singh Rajoana, who was convicted for the assassination of former Punjab Chief Minister Beant Singh, to life imprisonment.
Addressing a press conference, Congress leader Abhishek Manu Singhvi asked what was the BJP government's "commitment to basic values and principles".
Referrring to Rajoana, he said: "Here is a heinous offence of a constitutional post holder... here is a party which ignores the loss of 16 other lives."
On August 31, 1995, the then Punjab Chief Minister Beant Singh was killed in an explosion outside the Civil Secretariat in Chandigarh. Sixteen others also lost their lives in the terror attack in which Punjab Police employee Dilawar Singh had acted as a human bomb.
( With inputs from IANS )