David Smith said the firm's sales had fallen by 28%
Car manufacturer Jaguar has announced it is to axe up to 300 jobs at its Halewood plant on Merseyside.
The job losses come as it plans to end production of its X-Type model at the Jaguar Land Rover factory, which employs more than 2,000 workers.
Voluntary redundancies will be followed by a three-week shutdown due to "ongoing weaknesses in the industry".
Prime Minister Gordon Brown said: "We are trying to do what we can to replace lost jobs."
Discussing the issue in the Commons, Mr Brown said he hoped the Halewood plant would have a long-term future.
The Prime Minister added: "We... want to secure a future for Halewood and we have offered Jaguar Land Rover a grant of £27m toward the development of what are low-carbon Land Rovers at this plant, they would be produced there."
Jaguar Land Rover said it would be seeking voluntary redundancies at the plant, which will close for three weeks as part of an extended summer shutdown starting in September.
David Smith, chief executive of Jaguar Land Rover, said the latest job cuts were "necessary to protect other investment plans".
He said: "Our industry has been especially badly hit by the recession and the premium sector more than others.
"Jaguar Land Rover's retail sales fell by 28% in the past 10 months.
"We have taken unprecedented actions to cut costs including reduced production volumes, significant cuts to investment plans and some 2,200 job losses.
Gordon Brown has offered the plant a £27m grant to build the LRX model
"Ceasing production of the X-Type early, with further redundancies and temporary shutdowns at Halewood is necessary to protect our other investment plans."
Mr Smith confirmed that any further actions would be determined by the state of the market in the coming months.
Political leaders in Liverpool called for an "urgent and effective" response from the government, and urged plant managers to consider building the new greener-LRX model at the plant.
In a joint statement, Liberal Democrat council leader Warren Bradley and Labour opposition leader Joe Anderson said the manufacturing skills of the Jaguar workforce were "essential to the future prosperity" of the area.
Mr Bradley said: "We will be supporting the management at the plant to help secure production of the new green LRX vehicle at Halewood which would give the site a long term future.
"It is not only the jobs of the workforce that are at risk, but also those at companies in the supply chain who manufacture components for the plant."
Mr Anderson described the factory as a massive success story for the area and its workforce "a huge asset".
"It is vital that the whole region pulls together to offer whatever assistance and support we can to help the staff and firm through these tough economic times," he added.