Ryanair's call for talks with its Ireland-based pilots' union Forsa over labour disputes has been rejected, said the airline on Thursday.

Ryanair has received a notice from Forsa about a fifth strike to be held on Aug. 10, the company said in a statement.

The notice came just one day after Ryanair offered a meeting with Forsa on next Tuesday morning under the conditions that no more strikes will be called by the union before the proposed meeting.

Since Forsa has called for another strike before the meeting there is no point for Ryanair to meet with the union, said the statement, adding that Ryanair will notify its customers about the cancellations of 20 flights due to the strike, which will affect a total of 3,500 customers.

Ryanair condemned the strike announced by Forsa, a powerful trade union in the Irish public service sector, which represents the interests of Ryanair's Ireland-base pilots.

It has accused Forsa of being manipulated by a tiny handful of Aer Lingus pilots in the negotiations between the two sides.

Aer Lingus is the second largest airline in Ireland which is viewed as a rival of Ryanair.

Ryanair said in the statement that it was this tiny handful of Aer Lingus pilots who were behind the scenes for inciting the strikes and sabotaging the talks.

They did this because "they just want to damage Ryanair's business and our share price for the benefit of Aer Lingus", said the statement.

Ryanair also accused these Aer Lingus pilots of working behind the scenes with pilot unions in Sweden, Holland, Belgium and Germany to further disrupt Ryanair's business and its customers.

Ryanair's pilots based in Belgium and Sweden have announced that they will strike on August 10, a date that coincides with the strike date just announced by Forsa. Ryanair's pilots in Germany and the Netherlands have also voiced their support for the strikes launched by Ryanair's pilots in Ireland and could join the strikes any time in the near future, according to local media reports.

The recent strikes launched by Ryanair's pilots in Ireland first started on July 12 after they lost their patience with their employer over the talks on the improvement of their working conditions which mainly centered around a demand for base transfer, annual leave and promotions based on seniority.

The first strike was followed by two more one-day strikes on July 20 and July 24. The fourth one is due to come on Friday which has forced Ryanair to cancel 20 flights affecting a total of 3,500 customers.

The five strikes including the fifth one on Aug. 10 will lead to a total of 110 Ryanair flight cancellations, affecting at least 17,000 customers, according to Ryanair.