"Note to Mr Sangma - you are contesting elections to the highest office in the land, would it hurt you to maintain a measure of decorum?" Omar wrote on the micro-blogging site twitter.com.
Although Omar did not elaborate any further on the issue, the comment was apparently in response to Sangma's reported remarks in Mumbai that Rashtrapati Bhawan was being used as a dumping ground for 'failed' former Finance Minister Pranab Mukherjee.
"The Raisina Hill is being used as a dumping ground for the failed Finance Minister," Sangma told reporters yesterday at Mumbai while mobilising support for his Presidential bid.
Omar's National Conference, which is part of the UPA at Centre and leads the coalition government with Congress in the state, has pledged support for Mukherjee's candidature.
The Presidential elections will be held on Jul 19.