The Irish data protection watchdog has been accused of “paralysing" European Union efforts to crack down on privacy failings by Big Tech after long delays to the investigation of a string of complaints.

Ireland’s Data Protection Commission (DPC) has a backlog of 164 complaints against US tech companies, a report has claimed, with 98pc of major EU-wide cases awaiting a result. The delays have created a bottleneck for Europe’s General Data Protection Regulation (GDPR) laws. 

Johnny Ryan, one of the report’s authors at the Irish Council for Civil Liberties, said Ireland’s privacy authority had made it “impossible to uphold data rights and police how Google, Facebook, Apple and Microsoft use peoples’ data across Europe”.

However, the DPC questioned the accuracy of the report’s findings and said it had resolved half of the cross-border data complaints referred to it.

Graham Doyle, deputy commissioner at the Irish DPC, said: “The statistics included in this report are inaccurate."

The DPC has received more than 1,200 cross-border complaints from other data regulators since the GDPR was introduced in May 2018, he added, with over 600 of these resolved.

Dublin’s data watchdog, headed by commissioner Helen Dixon, has attracted criticism for the slow progress of its data investigations from advocates and rival data watchdogs. 

Dozens of US technology companies, including Google, Facebook, Apple, Microsoft and Twitter, have their European bases in Ireland, which is known for its beneficial tax regime. This makes Ireland the lead authority for the many European privacy investigations, with other European authorities forced to refer their cases to it.

The GDPR regime was criticised by some Irish politicians before it was introduced in 2018, and the country has also lobbied against efforts by US President Joe Biden to introduce a global minimum corporation tax. 

GDPR, the EU’s set of data rules, was introduced in 2018 with the aim of tightening up privacy protections and bringing in harsher fines for technology companies that harvested data. The rules allow for fines of up to 4pc of global turnover.

The Irish Council for Civil Liberties wrote to the European Commission and Ireland’s parliament calling for Dublin’s data watchdog to be reformed and strengthened.

In its report, the council said: “No other enforcers can assert their authority over the tech companies headquartered in Ireland and so they remain effectively out of the reach of the law."

It added that Europe had been left unable to police how Big Tech firms use data because of the DPC’s claimed failure action, and said that Ireland represents a “Wild West” when it came to privacy protections.

One exception to the general slow pace was a €225m fine meted out to WhatsApp earlier this month over transparency failings about how it shared information with Facebook. That fine, however, was increased by European authorities after rival regulators challenged Ireland’s ruling.

The findings come as the UK prepares to breakaway from Europe’s GDPR laws in the wake of Brexit.

Britain’s current rules largely mirror European law after its exit from the bloc. However Oliver Dowden, the Digital Minister, has confirmed plans to re-write Britain’s rules with a “light touch” framework to cut down on red tape.