New Delhi, Apr 6: Cautioning the Congress-led coalition that it might have to pay a "heavy political price" for spiralling prices, outside supporters Left parties and UNPA on Sunday announced a week-long joint nation-wide protest on April 16 against the government's "failure" to tame inflation.

At a joint press conference, leaders of these parties charged the government with "total betrayal of Aam Admi" (common man) and threatened "an element of militancy also" in the struggle.

They demanded strengthening of PDS, ban on futures trading in agricultural commodities, cut in customs and excise duties on oil and stringent action against hoarders of essential commodities.

"We feel the measures taken by the government so far are inadequate. The diagnosis of inflation is wrong," CPI(M) leader Sitaram Yechury said and asked the government to take immediate steps to "arrest this runaway rise in prices of essential commodities that are imposing untold misery on the common people".

CPI leader D Raja said if the UPA government did not take prompt and effective steps quickly, it might have to pay a "heavy political price".

He suggested said the struggle had to be sustained with "an element of militancy also", if needed.

Amar Singh said Samajwadi Party had in the past raised its voice jointly with the Left on various issues like Indo-US nuclear deal and this time "we are solidly behind the Left on the issue of price rise".

K Yerran Naidu (TDP) said the government was not functioning for the common man, on whose strength it came to power, and accused it of "total betray of aam admi".