New Delhi, Mar 28: The Left parties today alleged that the BJP was making ''deliberate attempts'' to weaken the Election Commission's authority and undermine all constitutional bodies in the country. Reacting sharply to BJP leader Pramod Mahajan's statement that the EC is not an ombudsman to decide on what issues are to be raised and how, they said it amounted to ''interference'' in the commission's independent functioning. Mahajan had termed as ''ridiculous'' the Congress representation to the EC protesting TV ads on the foreign origin issue and said the EC's role was to ensure impartial polls and non-violation of the model code of conduct. Bureau Report