Senior Congress leader P. Chidambaram on Wednesday expressed disappointment over Chief Economic Advisor (CEA) Arvind Subramanian's resignation, noting his views were brushed aside on many important issues including GST rates and he was not consulted before demonetisation."I am disappointed, but not surprised, that Dr Arvind Subramanian has decided to leave the government before the end of his term. Dr Arvind Subramanian was either not consulted or his views were brushed aside on many important issues," the former Union Finance Minister said in a tweet."It is no longer a secret that the CEA was not consulted before demonetisation. The CEA's views on GST rates and his report on the Revenue Neutral Rate (RNR) were rudely brushed aside and, as a result, we have an animal that is not GST," he added.Chidambaram also said: "I am sure that with age on his side, Dr Arvind Subramanian will return to serve under a future government.I thank Dr Arvind Subramanian for describing the UPA years of 2005-2010 as the 'boom period' of the Indian economy."Subramanian's term would not be extended any further as he wants to go back to the US due to family commitments, Union Minister Arun Jaitley said in a Facebook post on Wednesday.