Mr Thackeray had attended the NDA dinner last month where it was decided that the Prime Minister would lead the NDA into the general election of 2019.
Yesterday, at an internal meeting of the Sena, Mr Thackeray said it was Mr Paswan who had "forced these words into the NDA resolution that in 2019 we will fight under the leadership of Modi". Pointing out that there are still two years to go before the next local body elections, he said, "Why force leadership in such a hurry? This is not acceptable to the Shiv Sena".
Today, news agency Press Trust of India quoted Mr Paswan as saying, "In the NDA, there is consensus that not only for 2019, the Prime Minister's post is reserved for 2024 as well".
He also objected to Mr Thackeray's claim that it was he who had got the idea pushed into the NDA resolution. "Why is he saying that I proposed Modi's name for 2019 election in the last NDA meet that we had. He was also present there. He was the third member to speak as an ally," PTI quoted him as saying.
The Sena, which had started out as the senior partner of BJP in Maharashtra, has consistently lost ground in recent elections. While the party has continued sharing power with the BJP in the state and being an ally at the Centre, it has lately played the role of an in-house opposition.
After criticizing the BJP over a number of issues, including the Centre's handling of demonitisation and its choice of Sharad Pawar for Padma awards, the abrasive relation between the two parties had hit an all-time low during the Mumbai civic elections which they contested separately.
This week, not only Mr Thackeray, but two of his party leaders have hit out at the Prime Minister after the mutilated bodies of two soldiers were recovered at the Line of Control in Jammu and Kashmir. The party's senior leader Ramdas Kadam asked the Prime Minister to focus "more on security and less on elections". "As a nation, we have to take some decisions," another senior leader, Sanjay Raut, had said.
Even Mr Thackeray took a dig at the PM Modi, saying "With the people you do Mann Ki Baat. With Pakistan, you should do Gun Ki Baat," - a take-off on the title of his monthly radio programme.