They thought they had got over the worst once they had struggled through their eight-minute presentations on "Can there be a Third Way in foreign policy?" But there was one more hurdle. "Would you go ahead and publish a report if the No 10 Policy Unit and the Foreign Office didn't want you to?"
This was the awkward predicament faced by candidates applying for the position of director of the new Foreign Policy Centre. With luminaries such as Tony Blair and Robin Cook on the letterhead, and with Cook's special adviser and an adviser from the Policy Unit acting as chief inquisitors, such a blunt question about political allegiance should have come as no surprise.
The centre is not the only think-tank where you can detect high-level political "interest". Demos is seeking a new director to replace Geoff Mulgan, who resigned in October to spend more time with the No 10 Policy Unit. There are concerns that Mulgan is having a tough time severing his umbilical link to the organisation he helped found, and is lobbying hard for his chosen successor.
At the Institute for Public Policy Research (IPPR) meanwhile, a new Blairite director has recently been appointed to replace Gerry Holtham, a clever, Eeyorish man, who resigned in June to re-seek his fortune in the city. Early applicants received a quickie interview, taking less time than it would to hire a new secretary. A shortlist of three was drawn up. Then nothing for a month. Candidates waited for the second round. It never came. In October Matthew Taylor was anointed.
Taylor is seen by many as an Identikit Blairite: shorn hair, sharp suit and quivering bleeper. He has the CV to support the image: assistant general secretary of the Labour Party and director of policy during the election. It is a whispered secret that he was offered a post inside No 10.
Taylor's appointment may seem to confirm No 10's footballing tendency to delineate the world into on- and off-side factions, ousting awkward types, such as Holtham, and replacing them with the tried and trusted few.
But the reality is somewhat different. Realeconomik as much as Realpolitik influenced the selection of Taylor. Although some trustees were unhappy with the candidates, there was financial pressure not to grind through a further round of interviews: the IPPR needed a cash injection after the fund-raising lull left by Holtham's departure and Taylor, among his other skills, looked best able to deliver.
The biggest headache for think-tanks is that they offer a salary of only £35,000 or so but want to attract people with an unusually wide range of skills: political savvy, academic credibility, ideas and the ability to hustle for funds. Chatham House had to call in headhunters to find a new director. The increasingly influential new Centre for European Reform was lucky to attract Charles Grant as its director, after he took a pay cut from the Economist. The Foreign Policy Centre appointed 24-year-old Mark ("Cool Britannia") Leonard, formerly a Demos wunderkind, only after a trawl through the foreign policy community had failed. Many of those rumoured to have applied for Demos are already associated with it, such as Tom Bentley, a 25-year-old researcher, Helen Wilkinson and Ian Christie, the current deputy director. Demos hopes to appoint someone by Christmas. (Put your money on Bentley.)
Once in place, though, there is a real opportunity for think-tankers to become highly influential by engaging with a government whose thinking is still relatively inchoate on many issues. A tone of constructive criticism is more likely to pay dividends (and internal wages) than desultory shin-kicking.
In their pursuit of influence, the various think-tanks are adopting very different approaches. Though he passed the political loyalty test, Leonard thinks that "trying to second-guess what the government's agenda is may confer short-term influence, but ultimately this influence is limited because you are not changing the public debate. Think-tanks often work best by being outrageous, not second-guessing."
Leonard hopes to use the media as a "battering ram" to force through new conventional wisdom in foreign affairs, and wrestle influence away from the leather-armchair elites of Chatham House.
At the Fabian Society, the general secretary Michael Jacobs argues that "influence cannot be the criterion for how you choose what work you do". Jacobs, an environmental economist who landed the post last year after fighting off younger, newer Labour contenders, is some way from being an Identikit Blairite. Instead he recognises that he must tickle his members' ideological tastes as much as the government's, as they provide one-third of the society's cash. He describes his relationship with government as a hokey-cokey, "half-in and half-out".
Matthew Taylor, however, is keen to move the IPPR to the heart of political debate; he wants to shift the focus away from micro-policy on to bigger-picture projects, such as new technology, and to raise the institute's media profile.
The danger, as Eamonn Butler of the pro-free market Adam Smith Institute sees it, is that the IPPR will go the way of the Centre for Policy Studies (CPS). "It became so close to the government that it in effect became part of the Policy Unit and disappeared." As for his own think-tank, it does not seem to be suffering from a similar identity crisis: "We have the same relationship with this government as we had with the previous one," he claims.
Over on the right, the Institute of Economic Affairs is equally dismissive of all this talk of repositioning.
"We never position ourselves according to what the government is doing," explained David Green, the director of the health and welfare unit. "We want to encourage discussion about liberty and the market economy. We keep ploughing that furrow."