This happened due to the intense political movements for language-based states as well as a need to effectively administer a diverse country.

The enclaves of Daman and Diu were Gujarati-speaking areas due to mass immigration of ethnic Hindu Gujaratis following the end of Portuguese rule, and bordered the new state of Gujarat.

[7][8] Subsequently, Goa's first polls were held on 9 December 1963, and for this, Roque Santana Fernandes is popularly known as the "Father of Goan Democracy".

The United Goans Party wanted to retain independent statehood for the former Portuguese enclaves[10] The MGP had the support of the lower castes among Goa's Hindus (who were hoping for land reforms that would allow them to take over the property of their landlords) as well as the Marathi immigrants who had flooded into Goa to take jobs at the MGP's invitation (Portuguese had been replaced by Marathi so that government jobs could be given to immigrants from Maharashtra instead of to native Goans, which led to a population growth of almost 35% that decade).

[12] The MGP and politicians in Maharashtra were elated at the victory and touted it as a mandate that the majority of Goans were in favour of merger.

The United Goans Party, headed by Jack de Sequeira, also knew that if the issue was put to vote in the state assembly, merger was a foregone conclusion.

Sequeira visited New Delhi along other MLAs and impressed Nehru about the need of an opinion poll on this matter.

However Nehru died before Parliament could take this decision and Lal Bahadur Shastri succeeded him as Prime Minister.

A delegation consisting of MGP MLAs and Maharashtra's leaders went to New Delhi to convince him that a vote on the merger should be conducted in the Goa Assembly.

Again Sequeira along with other MLAs met Indira Gandhi and submitted a memorandum that such a monumental decision affecting the future of the State could not be left to legislators alone, but should be put before the people to decide.

[16] Purushottam Kakodkar, the president of the Goa unit of the Congress Party, used his personal equations with the Nehru family to lobby hard for a referendum with the central leadership.

UGP also demanded that expatriate Goans staying in other parts of India or the world, should be allowed to vote by postal ballot.

The president of India gave his assent to the Goa, Daman and Diu (Opinion Poll) Act on 16 December 1966 after it was passed in both houses of the parliament.

[4] Now that the referendum would be conducted, the anti-merger faction feared that Bandodkar may use the state's administrative and law-enforcement machinery to browbeat the anti-mergerists into submission.

They were convinced that the only way to overthrow the existing dominance of the Goan Catholic majority and the Gaud Saraswat Brahmins, was to merge into Maharashtra.

They had considerable influence due to their better education and economic prosperity, and were fearful that the merger would lead to their oppression by Hindus (e.g. beef ban, prohibition, etc.).

They mostly spoke in Konkani (although the upper class also knew Portuguese, French, English and Latin), and did not have any feelings for Marathi.

The pro-merger group received support from leaders of Maharashtra and North India, cutting across political lines.

[15] Sequeira toured extensively over Goa conducting public meetings explaining the anti-merger stand.

Uday Bhembre wrote a fiery column Brahmastra, took a stance opposing his pro-merger father.

[23][24] In the territorial capital of Panjim, the results were cheered by a crowd of 10,000, who danced in the streets carrying branches symbolic of victory, set off firecrackers, and created such a joyous disturbance that the government had to call in police with tear gas to restore order.

Their grievance was that the Opinion Poll only offered them status-quo as a self-administering union territory instead of full statehood that they desired.

Jack de Sequeira was criticized for agreeing to the clause in the referendum that did not confer full statehood to Goa.

The status of Konkani as the official state language was closely related to the issue of statehood for Goa.