In the cable dated November 7, 2007 released by WikiLeaks, embassy officials described Gandhi as being "unable to show principled leadership even when it might benefit her party at the polls and reveal Prakash Karat to be the extortionist he is."
The cable that criticises Gandhi and discusses whether the Manmohan Singh government would be forced to call general elections on the Indo-US nuclear deal issue, says: "Mrs Gandhi never misses an opportunity to miss an opportunity."
It says: "The Congress party, led by Sonia Gandhi, has proven especially cautious and nervous in the face of recent extortionist tactics by Prakash Karat.
With two huge confrontations in its future -- Parliament and Gujarat -- it will remain true to its cautious form by seeking first to gauge its levels of support before finally being forced -- if absolutely needed -- to take action."
It adds: "With the future of Indian foreign credibility hanging in balance, Sonia Gandhi has been unable to show principled leadership even when it might benefit her party at the polls and reveal Prakash Karat to be the extortionist he is. Mrs Gandhi never misses an opportunity to miss an opportunity."
Informing Washington that while remaining publicly restrained and taking care not to be seen as interfering with domestic Indian politics, the embassy said it will continue to meet with all political, business and civil society organisations to urge them to support the agreement.
"We will continue to press the UPA government on the need for early completion of the safeguards agreement with the IAEA. And, we will continue our efforts to remind the BJP that the US-India civil nuclear agreement is their deal, too," the cable says.
The cable discusses several scenarios in relation to elections in Gujarat, and whether the Congress would be able to retain its strength in the face of popular expectations of the BJP led by Narendra Modi once again emerging victorious.
It says: "If the Congress party can put in a healthy performance to make a dent in this BJP bastion, observers believe the Congress party will feel politically strong to risk (or even call) a mid-term national poll...
"If, on the other hand, the Congress party is trampled again in Gujarat and fails to improve on its 48 seats (out of 182 total seats in the assembly), it will feel vulnerable and will not be tempted to risk early elections.
It will then require extraordinary political courage for the UPA to carry out the IAEA talks, which (may) place its full term in office in jeopardy."