Uddhav Thackeray warned that if the "BJP continues its arrogance", the Shiv Sena will not hesitate to pull out of the alliance. (File Photo)

Shiv Sena Chief Uddhav Thackeray today threatened to pull out of his party's alliance with the BJP, launching a sharp attack on the partner at a rally ahead of civic polls in Kalyan-Dombivali, a Mumbai suburb.Mr Thackeray's threat came as Eknath Shinde, a Shiv Sena minister in the government of Chief Minister Devendra Fadnavis of the BJP, offered to resign on stage, saying he could "no longer suffer the humiliation" being meted out to the Sena by the BJP.Uddhav Thackeray did not accept the resignation, but said, "If the government becomes arrogant we will resign all together. Eknath Shinde will not resign alone."Mr Thackeray has made such threats before and Mr Fadnavis, 44, quickly dismissed it. "We have seen on television a cabinet minister making allegations and offering to resign. This is nautanki (drama)," Mr Fadnavis said.The Kalyan-Dombivali municipality election has become a direct fight between the two allies with the Shiv Sena deciding earlier this month to contest all 122 seats separately. The campaign for the November 1 election has been shrill and bitter.The two parties are allies both at the Centre and in Maharashtra, where the Shiv Sena helps the BJP make up numbers for a majority in the assembly. In assembly elections last year, the BJP won the most seats, 122, in the 288-member Maharashtra house, falling just 23 short of a majority.The run-up to the assembly elections saw the allies of many years fall apart. The result changed the balance of equations - the Shiv Sena, which won 63 seats, emerged as the number 2 party.The Sena had to swallow much pride to accept being the junior partner after years of leading the alliance in the state and even though it joined the state government, the relationship has been very strained since.The Kalyan-Dombivali civic elections are being seen as testing ground for the two parties to contest the Mumbai municipal corporation elections separately in 2017, in a final severance.