Mamata Banerjee asked where is the democracy in our country after the incident.

Firebrand orator Mamata Banerjee brought back memories of the good old Doordarshan days when she quipped Rukawat Ke Liye Khed Hai (Sorry for the interruption) as she extended support to former Uttar Pradesh Chief Minister Akhilesh Yadav, who was "detained" at the Lucknow airport and barred from boarding a flight to Prayagraj today.

The Samajwadi Party chief was headed for an event at the Allahabad University and had reached the Lucknow airport on time but when he was about to board a special flight, he was stopped from climbing the stairs of the aircraft by the UP police and a man in plain clothes.

Mr Yadav argued with the person and in a video put on his Twitter handle was heard warning "haath mat lagao (take your hands off me)" after which his security team pushed the man aside. Sources told NDTV the man was an Uttar Pradesh government official.

West Bengal Chief Minister Mamata Banerjee condemned the "arrogant attitude of the BJP leaders" and said that those who stop a former chief minister from meeting students shouldn't give lessons to others.

"If under Yogi Adityanath's rule, a former Chief Minister is not allowed to attend a college event then there is 'rukawat'. 'Rukawat ke liye khed hai.' There is such a situation in the country today that people are not allowed to go to places," Ms Banerjee told news agency ANI.

I've already spoken to @yadavakhilesh. We all condemn the arrogant attitude of the so-called #BJP 'leaders' who didn't allow Akhilesh to address the students. Even @jigneshmevani80 was not allowed. Where is the democracy in our country? And they are giving lessons to everybody! - Mamata Banerjee (@MamataOfficial) February 12, 2019

Tensions flared between Mamata Banerjee and the BJP after her government refused to grant permission to senior leaders of the BJP, including party chief Amit Shah and Yogi Adityanath, from campaigning in West Bengal. The chief minister repeatedly denied permission for their helicopters to land at the rally grounds.

The BJP protested this move by calling Mamata Banerjee "undemocratic". Holding an election rally is the constitutional right of every political party, they said.

Mr Yadav's description of his experience through images and videos compelled other opposition parties to censure the ruling BJP at the centre and in UP.Bahujan Samaj Party chief Mayawati, who recently announced an alliance with Akhilesh Yadav for the upcoming national election, also described the episode as "anti-democratic".

Extremely condemnable that Samajwadi Party President and former UP Chief Minister Akhilesh Yadav was stopped at Lucknow airport today in order to prevent him from attending programme in Allahabad. This is anti-democratic and an example of total dictatorship of BJP government. - Mayawati (@Mayawati) February 12, 2019

Telugu Desam Party chief N Chandrababu Naidu described it as the "high-handed behaviour" of the UP administration.

"Strongly condemn the high-handed behaviour of Lucknow authorities against Samajwadi party leader Sri Akhilesh Yadav. Another instance of BJP's intolerance against its political opponents. Really democracy is in danger," Mr Naidu tweeted.

Akhilesh Yadav, 45, was to attend the oath-taking ceremony of the students' union. The student wing of the Samajwadi Party holds the post of president of the university students' union. Mr Yadav said the authorities had already been informed about his travel plan in December.

Calling it "remote control politics of two-and-a-half men", Mr Yadav accused the government of putting his "house under surveillance, plotting blasts near the event venue in Allahabad and burning down the office of the students union president".

"When I looked out of my house at 6.30 am, I saw officials there," he told reporters after he left the airport.

The Prayagraj police, however, say Mr Yadav was denied permission to enter the university campus by its administration, fearing law and order problems.

"The Samajwadi Party should refrain from its anarchist activities. Allahabad University said that Akhilesh Yadav's visit may create law and order problem because of the dispute between student organisations. Hence, the government took this step," Chief Minister Yogi Adityanath said.

Within hours, protests started in Allahabad, Jaunpur, Jhansi, Kannauj, Balrampur, Jalaun, Azamgarh and Gorakhpur, where party supporters smashed windscreens of vehicles and clashed with the police. In Lucknow, protesters gathered outside the assembly complex and the governor's home. Roads were blocked in Gorakhpur, the home turf of Chief Minister Yogi Adityanath, and several of them were injured during these protests.