Which political party was expected to win the first general election in India?

Indian National Congress

The outcome of the first general election did not come as a surprise, as the Indian National Congress was widely expected to emerge victorious.

It was widely expected to win the first few General elections due to the following reasons:

Its inclusive nature.
Its coalition like nature.
Its solid organisational structure.
Its strong association with the national movement.
It had the ‘first off the blocks’ advantage.
Presence of charismatic leaders like Jawaharlal Nehru and other freedom fighters.
A well-organized machinery, spread all over India, etc.