Congress treasurer Ajay Maken said the party is exploring all legal options and would move the high court "very soon".
"The BJP government has deliberately chosen the timing of this to coincide with national elections," Maken told PTI.
He said the I-T tribunal order freezing Congress's funds is "an attack on democracy" as it has come just ahead of national elections and has left the principal opposition party without funds to contest elections
"How can one expect fair elections in such a situation when funds to the tune of Rs 270 crore have been freezed or taken away by the Income Tax authorities from Congress party's accounts," he asked.
Maken claimed that the party is now left with "negligible" funds to spend during Lok Sabha elections or for its day-to-day functioning.
He claimed that the BJP or any other national political party has never in the history of the country paid any income tax penalty.
"Then why single out the Congress party," the Congress treasurer asked.
Confirming the order, Congress' legal cell head Vivek Tankha said the Tribunal has not even followed its own past precedents in this regard and the party will be approaching the High Court soon.
"We are disappointed with the Income Tax Appellate Tribunal order. We will be moving the High Court very soon. They have not followed their own past precedents in granting relief on payment of 20 percent penalty and that too to a national party which is now on the verge of contesting national elections, which is going to be notified soon," Tankha told PTI.
He appeared before the tribunal on behalf of the party appealing against the I-T authorities order imposing penalty worth Rs 210 crore for alleged discrepancies in I-T returns for previous years. Later, the I-T department asked all bankers of the Congress party to pay to the Income Tax department for penalties imposed by the department.
The Congress had earlier termed the Income Tax authorities' decision as "tax terrorism" coming ahead of general elections only to cripple the funds of the principal opposition party.
The Congress had earlier alleged that the Income Tax department has "withdrawn" a sum of Rs 65 crore from its accounts in different banks "undemocratically" and claimed that it has freezed another Rs 205 crore of its funds, totalling Rs 270 crore.
Maken had earlier claimed that "democracy will be over in the country if the action of probe agencies went unchecked" and said the Congress has full faith in the judiciary and would seek relief from them.
The accounts, including that of the Indian Youth Congress, were frozen on an Income Tax demand of Rs 210 crore for 2018-19, an election year, he said.
He said the Congress received a total of Rs 142.83 crore in 2018-19, of which oly Rs 14.49 lakh was given as cash by ex-MLAs, ex-MPs and others from their monthly salaries as donation to the party. According to him, the party filed its Income Tax return for the concerned year a few days late and that is why this action.
The Congress has been raising funds through crowd-funding and has launched campaigns in this regard, ahead of Lok Sabha polls. The party has said that its funds collected through crowdfunding have also been freezed by the tax authorities.
Congress president Mallikarjun Kharge said in a post on X, "Power drunk Modi Government has frozen the accounts of the country's largest Opposition party - the Indian National Congress - just before the Lok Sabha elections."
"This is a deep assault on India's Democracy," he added.
The Congress also alleged that the BJP was attempting to "murder democracy" and drag the country to a "dictatorship raj".
"An autocratic Modi Government is capturing democracy through extortion and financial terrorism," he had said earlier.