Addressing party workers here, Singh said "our friendship with Shiv Sena is very old and will continue in future. Now a days, many parties are taking Modi's name. Oh brother, why are you offering your unsolicited support to us? You either become part of NDA alliance or merge with BJP."
Without naming MNS, Singh further said nobody should do the politics of misleading the people.
He also stated that as the BJP president, he was not "aware" of any support declared by MNS to Modi for the post of the Prime Minister.
"I have not mentioned any party in my address," he said.
The comments by Singh are seen against the backdrop of displeasure expressed by Shiv Sena president Uddhav Thackeray over BJP leader Nitin Gadkari's meeting with Raj Thackeray for persuading the MNS chief to join BJP-led alliance.