Rating agency Moody's today said the Rs 20,465 crore tax demand raised on Cairn India is negative for its parent company Vedanta Resources. "The tax dispute comes at a time when Vedanta is already struggling to stave off the effects of weak oil prices. If the liability materialises, Vedanta's credit profile would be weaker than the parameters required by its current rating…" Moody's VP and Senior Credit Officer Alan Greene said. Last week, Income Tax Department has slapped a Rs 20,495 crore tax demand on Cairn India Ltd for allegedly failing to pay taxes on gains made by its former parent (Cairn Energy) in a share transfer transaction about eight years ago.