The power behind the throne or 'Eminence Grise', the phrase used by Martin Ardbo, one of the Bofors officials, in his diaries to describe the role of Arun Nehru in the Rajiv Gandhi government that came to power in 1984.
During that period, although Rajiv Gandhi was both prime minister and Congress president, Nehru wielded so much power that several decisions got taken without Rajiv Gandhi knowing about them.
Yesterday, newly-elected MP Rahul Gandhi said there would not be two poles of power in the new government. However, it is hard to understand how the government will prevent this.
How the Congress will handle a new bipolar setup -- represented by Prime Minister Manmohan Singh and Congress President Sonia Gandhi -- and how will it manage functioning and decision-making is something that is already worrying party managers.
The first problem will be floor coordination. "For a cue, Lok Sabha mein MPs kiska moonh dekhnge -- Soniaji ka ya Doctor Saheb ka?" (For a cue, whom will the MPs lend their ears to -- Dr Manmohan Singh or Sonia Gandhi?), asked an MP.
Seating arrangement will be a problem. As prime minister, Dr Singh should occupy Atal Bihari Vajpayee's seat in the Lok Sabha.
But that position will now be occupied as Sonia Gandhi in her capacity as Leader of the House and Congress parliamentary party chief. This already represents a dimunition of the position of the PM.
Will ministers look to the prime minister or the Congress president? "As long as communication between the PM and the CP (Congress president) continues unhindered, there will be no problem. But there will be many who will want to ensure the relationship doesn't work", warned an MP.
This has happened before. During PV Narasimha Rao's premiership, Arjun Singh, Narayan Dutt Tewari, Sheila Dikshit, Rangarajan Kumaramangalam and others floated the Congress (Tewari) in a bid to exploit precisely this pro-Sonia Gandhi sentiment in the party in a bid to oust Narasimha Rao.
Their 'convention', which they hoped Gandhi would inaugurate, went kaput as she never turned up, unwilling to provide leadership to a faction of the Congress.
In the past too, within the Congress party, there was dual authority -- the prime minister and the party president were separate individuals. When Indira Gandhi was prime minister, DK Borooah was Congress president.
However, the balance of power is tilted in favour of the party in this regard. Tackling the demands of the party when the PM and the party president are two different people with different agendas could be a problem.
During Sitaram Kesri's tenure as party president, it was Congress which drove many government decisions. Shunting out H D Deve Gowda as PM and replacing him with I K Gujaral was Kesri's way of responding on behlaf of the party. This led to the emergence of many unhealthy extra-constitutional coteries.
MPs are also worried about decision-making by the Cabinet. Will every decision have to vetted by 10 Janpath, and will the party become a super cabinet?
A working relationship with the allies is going to be crucial to the running of the government and both the Congress and the allies will now have to get used to two poles of power - the Congress president and the prime minister.