Underlining the importance of grassroot-level workers in BJP, Prime Minister Narendra Modi on Tuesday said that it is a matter of pride for the party to be the world's largest political outfit.

"We are proud of the fact that BJP has a government in 19 states of the country. UPA government never allowed a BJP-led state to function. Congress has only divided the nation. We have to eliminate the politics of votebank," PM Modi said in Bhopal while addressing workers at the mega rally.

In an apparent reference to Congress's allegations on Rafale deal, the prime minister further said, "Opposition indulges in mud-slinging because it finds it easier than debating on issues like development."

BJP chief Amit Shah also launched a blistering attack on Congress at the party's massive show of strength. Terming Manmohan Singh-led UPA government a 'failure', the Bharatiya Janata Party national president said that Rahul Gandhi is just 'daydreaming' of winning polls.

The prime minister launched the mega congregation of BJP workers, an event which comes just ahead of the Assembly polls in Madhya Pradesh.

The 'Karyakarta Mahakumbh' (grand assembly of party workers), is being held on the occasion of birth anniversary of Hindutva icon and Bharatiya Jana Sangh (BJS) co-founder Pandit Deendayal Upadhyaya.

The event, organised at Jambooree Maidan in the BHEL locality, is said to be the "world's largest congregation of political workers," state BJP spokesman Sarvesh Tiwari said. "BJP president Amit Shah will also address party workers on the occasion," he said.

The venue has been named as "Atal Mahakumbh Parisar" in memory of former Prime Minister Atal Bihari Vajpayee, who passed away in New Delhi in August.

Modi arrived at the Bhopal airport around noon and reached the venue in a helicopter along with other BJP leaders to avoid inconvenience to people, party leaders said. The prime minister will remain in the state capital for nearly three hours, they said.

BJP workers from 65,000 polling booths spread across the 230 Assembly seats in the state will take part in the programme, said Rajnish Agrawal, another state BJP spokesman. An exhibition hall named after BJP leader and former Union minister, late Anil Madhav Dave, has also been set up at the rally site.

Close to 12,000 buses and 8,000 private vehicles have been engaged to ferrying party workers as a part of arrangements for the mega rally. The party have also installed 45 LED screens to telecast the speeches of PM Modi, Amit Shah and others. A makeshift office has been built on the side of the stage, where the visiting leaders would have consultations with the party state functionaries.

The venue is dotted with ten different pandals designed in a manner which enables the visiting leaders to have a clear view of even the last rows. Arrangement for lunch has been made for the party workers in a separate pandal.

"It will showcase the journey and works of BJP stalwarts, including Vajpayee, Modi and Madhya Pradesh Chief Minister Shivraj Singh Chouhan," Agrawal said.

In the exhibition, BJP and BJS stalwarts — Upadhyaya, Syama Prasad Mookerjee, Vajpayee, Rajmata Vijayaraje Scindia and Kushabhau Thakre - have been depicted as the five strong pillars of the BJP, he said. The Bharatiya Janata Party (BJP), established in 1980, is the successor party of the BJS.

The party has booked nine special trains from different parts of the state to bring BJP workers for the event, Agrawal said. Police have made elaborate security arrangements for the high-profile event and also Modi's visit.

"We have made adequate security arrangements for the visit of Prime Minister Narendra Modi on Tuesday by deploying nearly 6,000-strong force, including 4,000 personnel from the central and reserve forces," Inspector General (IG) Bhopal Jaideep Prasad told PTI.

Nearly 22 senior IPS officers have been deployed to coordinate security details, he said. Along with Madhya Pradesh, Rajasthan, Chhattisgarh and Mizoram will also go to polls by the year-end.

Modi and Shah, two star poll campaigners of the BJP, are in Bhopal days after Congress chief Rahul Gandhi visited the state capital. Gandhi held a roadshow and later addressed Congress workers and office-bearers during his September 17 visit.

Both the national parties are in poll campaign mode in the state, where the BJP is in power since 2003. While the saffron outfit will seek a fourth straight term in office in the year-end elections, the Congress will look to wrest power from the BJP in a state which was once its stronghold.