The union representing Thomas Cook retail staff says it has “full confidence” in an inquiry into the collapse after accusing the business secretary of failing to answer why the company was allowed to go to the wall.

Transport Salaried Staffs’ Association general secretary Manuel Cortes believes the Commons business committee will do a “very thorough job” after meeting its chair, Rachel Reeves MP.

The committee is due to begin its deliberations next week.

Cortes has called for business secretary, Andrea Leadsom, other ministers and Thomas Cook bosses, including chief executive Peter Fankhauser, to be brought before the committee.

He said: “I know they will be keen to determine whether government intervention could have spared the loss of 9,000 jobs in Britain, stopped the repatriation of over 150,000 holidaymakers and ruined the holiday plans of 320,000 others who had booked their holiday with the company.”

So far, at least 5,000 applications for redundancy have been processed with £18.4 million paid out. But there are still a number of ex-employees yet to apply.

Cortes said business secretary Andrea Leadsom, had “abysmally failed to answer any of the questions about how and why Thomas Cook was allowed to go to the wall.”

He had previously called for her resignation for not holding any discussions with Cook before it went out of business.

The TSSA is also seeking answers as to why the government chose not to offer financial assistance or intervene to salvage the company, or parts of it, as the German, Spanish and Portuguese governments have.

Cortes said: “It also appears very strange that it wasn’t just governments from other European counties who’ve been prepared to intervene to save parts of Thomas Cook. Fosun – a private Chinese investor – was willing to put £450 million into the business to ensure its survival.”