The Prime Minister, who is keen to appoint a full-fledged foreign minister before he departs for Brazil and Cuba on September 10, will stick to the Congress tradition of choosing someone with “experience, erudition and gravitas” — a criteria that has made veteran Congressman Karan Singh a front-runner for the post.

The twin decisions to appoint Shiv Shankar as foreign secretary and Shyam Saran as special envoy for the conclusion of the tricky Indo-US nuclear deal are both signals of a ‘pro-active’ Prime Minister as far as foreign policy is concerned. A new foreign minister would be in keeping with this approach. That is why it is unlikely to wait for the more delicate and difficult task of a much-awaited Cabinet reshuffle.

While several names have been doing the rounds, the Congress leadership’s insistence on “seniority” has narrowed down the options before the Prime Minister, sources said. Kapil Sibal, considered close to the PM, may have the requisite erudition and aplomb, but is viewed as a ‘Johnny-come lately’ within the party.

Minister of State for Foreign Affairs Anand Sharma, for instance, is far senior to Sibal when it comes to the number of years in the party. Sharma was a Youth Congress leader during Indira Gandhi’s time and is believed to be keen on a promotion to Cabinet-rank if the contender is Sibal. One reason, perhaps, that Sharma has repeatedly said that the MEA was doing just fine over the last nine months and there was no pressing need to appoint a foreign minister.

Maharashtra Governor S M Krishna was a possible contender, but he has little ministerial experience at the Centre. Besides, he is not a member of either House of Parliament. In fact, with no Rajya Sabha vacancies on the anvil till 2008, it is difficult to induct veterans such as Krishna or Veerappa Moily or other ‘non-MPs’ who are keen to return to the centrestage, a senior Congress leader admitted.

Although P Chidambaram and Kamal Nath are counted among the “young” in the Grand Old Party, both are fairly senior so far as ministerial experience is concerned. In fact, both have been Union ministers much longer than, say, Arjun Singh, who spend his early career in state politics and did a stint as Governor before joining the Central government. But the Prime Minister is quite happy with Chidambaram as Finance Minister; even if he were to be shifted at some later stage, party insiders feel, it would be to a ministry that demands organisational expertise (such as Home Affairs) rather than diplomatic skills.

With foreign affairs increasingly tied up with international trade and commerce, Kamal Nath has been eyeing the slot. But he does not quite fill the “erudition and gravitas” requirement, according to party veterans. In view of the “seniority” criteria, the Prime Minister had initially sounded out Pranab Mukherjee — the minister with the maximum experience in the UPA government — for the post. But Mukherjee, reportedly, was not too keen. Besides, both the PM and Sonia Gandhi lean on Mukherjee a great deal and agreed that it was more important that the Defence Minister is on call at all times, something that would not be possible for a foreign minister.

Apart from his seniority, Karan Singh has the advantage of sharing a good rapport with both the PM and the Congress chief. But his disadvantage, some feel, is that he “belongs to a bygone era” and may prove out of tune with the need of the times. That view too is being taken into consideration, sources said, underlining that the race for the post was still wide open.