Shut your eyes in the call centre at Facts International and the cacophony of voices could pass for the hubbub in the House of Commons before a debate.

The 200 interviewers sitting in their small wooden booths are conducting nationwide polling for research consultancy ComRes this month, with the results to be published on ITV and the Daily Mail. Earlier they carried out an exclusive election survey of Kent voters for the KM Group.

Chief executive Crispin Beale is pleased but not too pleased.

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He has just turned away two last-minute requests for research from private clients. The firm is operating at capacity.

“We are just getting busier and busier,” he said. “We won’t take on work we can’t deliver well.

“We have times like now where we are creaking at the seams and are open every possible hour. Then we have periods where all our clients have spent their budget at the end of the financial year and don’t want to do interviewing.

“Some weeks you could do with 1,000 people and others it is only a few hundred.”

Business is booming at Facts, which celebrated its 30th anniversary this month. It has a turnover of almost £8.5 million and a wealth of private clients ranging from local companies to high street banks, utility companies and supermarkets.

International demand is so strong, the business opened its first office in Sydney two years ago to offer a round-the-clock service.

Its brief can be as simple as helping to knock on doors through to designing a questionnaire and reporting the results.

It is the largest private employer in Ashford with about 60 full-time staff and more than 200 interviewers a day – there are more than 1,000 on their books – many have been there for decades.

Its first employee, Barbara Palmer, who joined as a coder in 1985, remains at the business to this day.

“Our biggest challenge now is growth,” said managing director Emily Kettle, an Ashford girl who first joined the firm in 1995 as an interviewer during holidays while studying at Reading University.

“We want to grow and stay in Ashford, but it depends on what our options are.”

The company’s bright pink office in Henwood industrial estate is full to the brim, with expansion into its car park the only realistic option to develop more space for the call centre.

The downside of that is compromising on the free car parking it can offer staff. Discussions are ongoing with the council about making use of a pay-and-display car park across the road at a discount rate. Bosses do not want to split up departments into different buildings.

“I’m loathe to do that because you lose the communication,” said Mrs Kettle.

“You don’t get that free dialogue. If you have to change a question for a client you can whizz out and get it done. It would be a grave day if we split the two. We just need to keep an eye out for premises.”

The firm’s growing pains are in stark contrast to when it was bought by Chime Communications in 2007 as a break-even fieldwork provider, picking up ad-hoc jobs from other agencies.

Founder Barbara Lee, who remains the landlord of its current office, launched the company at Willesborough Business Centre on the site of the former hospital in 1985, where managing director Emily Kettle was born.

It opened and closed an office in Canterbury inside two years but still won contracts for American newspapers polling on events like Princess Diana’s death and taste testing for Coca-Cola Vanilla.

Its takeover by Chime, whose VCCP branding experts came up with the ComparetheMeerkat and O2 Be More Dog campaigns, came shortly before the recession wiped out much of its competition.

Mr Beale said: “Many clients decided it wasn’t efficient to do things in-house. They realised they could save money by putting market research out to a company which does this professionally day-in-day-out.

“We have the economies of scale and with clients moving fieldwork out, we could expand the call centre.

“Telephone interviewing in the UK is in slight decline, but a combination of companies outsourcing their internal marketing and competitors saying it was not core business, meant we picked up a much greater share of that declining market.”

Mrs Kettle said: “We have had to be more innovative. Clients were doing huge programmes but now everything has a smaller margin and people want it quicker.

“A lot of our companies are phoning on a Friday saying they have a board meeting on Monday and need some quick results.

“We are constantly being pushed, but we have not lost sight of our core offer.

“If you don’t connect with that customer or person immediately you lose your chance..." - Emily Kettle, Facts International

“We are looking to work more with companies but we have not forgotten that our bread and butter is working for other agencies and offering fieldwork and data collection.”

Being a telephone interviewer is a tough job, as managing director Emily Kettle remembers too well.

“You may be ringing someone in a business who is really busy,” she said.

“You have got to be someone who can make a connection straight away. You have got to be openly engaging. That’s the secret.

“If you don’t connect with that customer or person immediately you lose your chance.

“We do a lot of tone of voice training. You have only got your voice on the phone. People need to sit up and be proud of what we are doing.

“You have also got to be a good listener. A lot of our clients want a lot more conversational interviews.

"We are putting the respondent in control so you can’t just have someone who goes ‘yep, yep.’ You need someone who can think of discourse markers like ‘ok, thank you for that, now...’” to make it more conversational.

“Also you need to be knowledgeable. If someone asks you ‘what’s a hung parliament?’ you have to be able to tell them.”