The new boss of passport and banknote firm De La Rue has pledged a "full review" of the business and ramped up cost-cutting as the group revealed it slumped to a half-year loss.

De La Rue posted a £12.1 million pre-tax loss for the six months to September 28 against profits of £7.1 million a year earlier.

Chief executive Clive Vacher said the group had been hit by a raft of management changes and an increasingly competitive banknote printing market, but is expecting a better second-half performance.

The group is forecasting operating profits of between £20 million and £25 million for the full-year.

Mr Vacher said: "The business has experienced an unprecedented period of change with the chairman, CEO, senior independent director and most of the executive team leaving or resigning in the period.

"This has led to inconsistency in both quality and speed of execution.

"The new board is working to stabilise the management team, which we believe will take some time."

He added: "Between now and the end of calendar first quarter 2020, we will complete a full review of the business and design a comprehensive turnaround plan for the company."

Shares in De La Rue plummeted 18% in early trading after its first-half results.

Trade union Unite said De La Rue's warning over its future was worrying for its staff and should be "ringing alarm bells" across government.

De La Rue has a 250-strong workforce at its plant in Gateshead in Tyne and Wear which suffered job losses in the summer after losing out on the UK passport contract last year.

The company also prints Bank of England banknotes at Debden, Essex, where it employs around 150 staff.

Unite national officer Louisa Bull said: "The potentially precarious future of De La Rue, a major UK manufacturing company, should be ringing alarm bells across government.

"Unite will be doing all it can in supporting our members at this very difficult time and will continue to campaign strongly to keep vital printing work in the UK.

"We have previously criticised the government's short-sighted and blinkered decision to award the printing of post-Brexit UK passports, worth £490 million, to French-Dutch firm Gemalto as it seriously undermined the financial viability of the Gateshead operation."