Onion is selling for Rs 30 a kg in some parts of the country, as supply of the edible kitchen bulb has been choked by hoarders betting on further price rise due to floods in the main producing states of Karnataka and Maharashtra, government officials said.

Onion prices have shot up by 67 per cent in Delhi from last week's level, 50 per cent in Mumbai and Kolkata, according to the government's own data on retail rates.

However, the government's rates reflect on the lower side of the prices quoted by retail traders.

For instance, while the Department of Consumer Affairs listed the price at Rs 25 a kg, the commodity is being sold by vendors at a minimum of Rs 30 a kg in the national capital.

"Arrivals in mandis have declined while demand is the same leading to high prices," said Surender Babu, a trader at Delhi's Azadpur mandi.

Electioneering is about to peak in Maharashtra, Harayana and Arunachal Pradesh for the October 13 assembly elections.

While political parties are raising the campaign pitch, the onion prices have not really become an election issue yet.