The controversy started over the recent issue of Time magazine dubbing Singh as an "underachiever", which prompted BJP to hit out at the Congress President who is also UPA chairperson.
"We would like to make it very clear that Sonia Gandhi cannot escape the blame because she has given the political authority to (Prime Minister) Manmohan Singh on account of which India has suffered because of mal-governance, corruption and under-development," the party's chief spokesperson Ravi Shankar Prasad said.
Prasad said the magazine has stated only the "obvious". "This is nothing new. The common man of the country has been speaking this for a long time that he (the PM) has practically no achievement to his credit.."
Stung by the criticism, Congress delved into a 2002 article from Time, which spoke of Vajpayee in disparaging terms.
Ridiculing BJP for treating Time as their "latest Bible", Congress spokesperson Manish Tewari asked whether it also endorses remarks by the same journal in 2002 that had attacked Vajpayee.
"I want to ask BJP, which has made Time magazine their latest Bible, that do they also endorse the remarks made by the same journal on Jun 10, 2002, about the then Prime Minister Atal Behari Vajpayee. I found portions of the article, too offensive," Tewari said in a bid to blunt the opposition attack.
JD-U chief Sharad Yadav asked the government to "introspect" over its support to the open market economy.
"Time is the patron of capitalism. They want FDI. It is a pressure tactic. Their opinion has no meaning here as it is not going to benefit the poor here," Yadav said.