Unions in Berlin have claimed that Ryanair violated airport safety rules when crossing a picket line to minimise disruption to its services during a baggage handler strike.

German services union Verdi has vowed to take legal action against the Irish firm - but Ryanair argues that it has no case to answer.

"The airline flew in its own staff that, without any security training and with day passes, are now operating on the Schönefeld apron,” said Mr Enrico Rümker, Verdi general secretary (as quoted in The Irish Times).

Ryanair flew staff from other locations to Berlin to minimise disruption. The union says that it documented staff from the airline loading and unloading air crafts by hand and without the required safety gear and that it has sent evidence of these alleged rule breaches to German authorities.

“In order to prevent further disruption to our customers, we (along with other airlines) positioned a number of fully qualified and authorised ground handling staff to dispatch our Berlin aircraft," Ryanair told Newstalk.

"These union claims are false and their members have no business accessing the airport and ramp when they are not working," it continued, referring to the claim that its staff had violated the airport's rules.

"It’s a disgrace that Berlin customers and visitors are having their travel plans disrupted by tiny numbers of unions, who are holding Germany’s capital city to ransom and we call on the German Government to intervene and prevent any further disruption,"  the statement added.

We regret that we have been forced to cancel a number of flights to/from Berlin Schonefeld Airport today. Read more: https://t.co/oU3o8LdLDm pic.twitter.com/zxqGD1U6cr

— Ryanair (@Ryanair) March 14, 2017

Verdi currently offers 18 hours warning before engaging in industrial action - it has warned that Ryanair's actions mean that it will consider snap strikes in the future.

It is seeking wage increases and other reforms for 2,000 ground staff at Berlin's Tegel and Schönefeld airports.