Mumbai, Jan 13 (IANS): The Shiv Sena will observe "Pratigya Divas" (Pledge Day) on Jan 23, its founder-patriarch Bal Thackeray's birth anniversary, at a mass rally in the Maharashtra capital, the party president said Monday.

Shiv Sena president Uddhav Thackeray said this year he has appealed to all party workers to join the mega-rally at Somaiya Ground in central Mumbai, instead of organising various small functions in their localities, and take a pledge to fulfil the late Bal Thackeray's dreams.

Responding to a question, Uddhav Thackeray made it clear it would not be a show of strength to rival its ally Bharatiya Janata Party's "Maha-Garjana Rally" (great roar rally) held here Dec 22, which was addressed by its prime ministerial candidate Narendra Modi.

"For us, Jan 23 is an auspicious day, like Dassehra or the Shiv Sena foundation day. There are a lot of emotions attached to that day, and the party is like a big family," Uddhav said.

"We know whom to show our strength to. We will contest the elections with the determination to win. I shall fulfil the responsibilities entrusted to me and will not allow the Shiv Sainiks to feel demoralised," he said.

Replying to a query on whether the BJP would be invited, he made it clear that it will be a rally for the Shiv Sainiks to take a pledge.

The BJP had kept out its ally, Shiv Sena, from Modi's Dec 22 rally.

"We are here to serve the people and we can do it better if we are in power, though the Shiv Sena's vision is not just to win elections. Our rule (1995-1999) was the best. We need to be alert and not become complacent. This is what will be our pledge Jan 23," he declared, setting the tone for the ensuing 2014 Lok Sabha elections, followed by Maharashtra assembly polls later this year.