The Dravida Munnetra Kazhagam (DMK), led by MK Stalin, is considering taking all routes, including legal, to ensure that bypolls in all 21 constituencies are held along with Lok Sabha elections.

As of now, the Election Commission has said bypolls in 18 constituencies will be held on April 18, barring three seats which are under litigation.

The DMK on Tuesday moved the Supreme Court with the plea that the Election Commission conduct bye-elections in the remaining three constituencies as well.

The total number of assembly seats in the state is 234, but with 21 vacancies, the number is reduced to 213.

With just 18 of the 21 constituencies going for bypolls, the ruling AIADMK, led by Edappadi K Palaniswami and O Panneerselvam, which currently has 114 MLAs has to technically win two of the 18 constituencies to ensure that it reaches the halfway mark of 116.

However, three AIADMK MLAs who are part of the 114 lawmakers in the assembly have openly sided with VK Sasikala’s nephew TTV Dhinakaran, meaning their loyalty to the ruling party is uncertain.

Three more independents who contested under the AIADMK symbol have been ambiguous about their positions.

A source in the AIADMK said the party should win more than 11 seats to ensure it was safe till 2021 when the government would complete its five-year tenure.

After DMK patriarch M Karunanidhi’s demise, the party and its allies have 97 MLAs. Top DMK sources said if the DMK won all the 21 bypolls, then it would have the majority (118) to form the government.

With the three bypolls delayed, the DMK may not be able to get the requisite number, precisely the reason why the Opposition is demanding bypolls in the all the 21 constituencies.

The trend of the ruling party winning bypolls was reversed in RK Nagar elections, where Dhinarakan won as an Independent in December 2017.

Besides Karunanidhi’s home constituency of Tiruvarur, the 17 other seats slated for bypolls were won by the AIADMK in 2016, a thumping victory for Jayalalithaa that gradually eroded due to factionalism in her party after her death.

It first took root when O Panneerselvam rebelled against the growing clout of VK Sasikala in his “Dharmayudh” in early 2017.

By September that year, Dhinakaran had pulled out 18 of his loyalists in protest against the merger of the Panneerselvam and Palaniswami factions.

The AIADMK has been facing a constant threat to its strength in the assembly for over 17 months now.

The bypoll is an acid test for the Edappadi K Palaniswami government and also the leader of opposition, Stalin, as this will be the first major electoral contest in the absence of J Jayalalithaa and M Karunanidhi.