Severe disruption was expected across Germany this morning, as more than 4,000 Lufthansa pilots walked out in a dispute over job security.

As many as 3,000 flights have been cancelled, with the German flag-carrier warning passengers to expect delays both domestically and internationally.

The strike is expected to last four days.

Pilots at Lufthansa, Lufthansa Cargo and Germanwings – the carrier’s low-budget subsidiary – downed tools at midnight, following a decision by Vereinigung Cockpit, the pilots’ trade union, to reject the offer of further talks.

Of the 1,800 flights offered daily by the airline, 1,000 are expected to take to the air today. Managers with appropriate airline licences and resources at regional subsidiaries are being drafted in an effort to alleviate staff shortages.

The stoppage will cost at least €25m (£20 million) a day, Lufthansa has said.

Lufthansa’s pilots voted overwhelmingly for strike action, following concerns the airline could try to cut staff costs by shifting jobs to foreign subsidiaries. Such concerns have been heightened by the recent acquisition of both British Midland Airways and Austrian Airlines, where German staff fear the airline could outsource jobs. 

However, the airline argues the number of pilots in Germany has increased by 20 per cent since 2001; principally through the expansion of its network through acquisitions.

The airline last week offered pilots assurances that their jobs would be secure through at least 2012.

Passengers on domestic flights were being rebooked onto trains this morning, while international passengers were being transferred to Star Alliance partners in efforts to get them to their destinations.

Efforts were being hampered this morning, as some of those pilots expected to break the strike failed to report for work, according to reports.