Claim

Uddhav Thackeray campaigned saying he would form a government with the BJP, and then went and allied with the Congress instead.

“जो उद्धव ठाकरे चुनाव में जाकर कहते बीजेपी के साथ सरकार बनाऊंगा। फिर चले जाते कांग्रेस के साथ।”

Rationale

The record confirms the core of the claim: Shiv Sena led by Uddhav Thackeray campaigned in the 2019 Maharashtra election as a pre-poll BJP ally (Mahayuti), then after the results broke with the BJP over the CM post and formed the Maha Vikas Aghadi government with the Congress and NCP in November 2019. The claim accurately compresses these well-documented events (it omits the NCP, but the Congress alliance is factual).

Evidence

• https://en.wikipedia.org/wiki/2019_Maharashtra_Legislative_Assembly_election Shiv Sena under Uddhav Thackeray contested the October 2019 Maharashtra assembly election in pre-poll alliance with the BJP (NDA/Mahayuti), which won a majority; after a dispute over the Chief Minister's post the alliance collapsed, and on 28 November 2019 Shiv Sena formed the Maha Vikas Aghadi government with NCP and Congress, with Uddhav as CM. ✓ reachable · archived
• https://en.wikipedia.org/wiki/Shiv_Sena Confirms Shiv Sena fought the 2019 polls allied with BJP and subsequently broke away to govern with Congress and NCP. ✓ reachable · archived