An appeal by Graham Dwyer against his conviction for the murder of Elaine O'Hara is likely to be heard in the autumn. Photograph: Collins Courts

The Cabinet is likely to approve emergency legislation on Tuesday to deal with the fallout from convicted murderer Graham Dwyer’s successful appeal to the European Court of Justice (ECJ) on Garda access to mobile phone data.

The legislation is likely to be rushed through the Dáil in an unusual Friday sitting this week.

Dwyer was convicted in 2015 of murdering Elaine O’Hara. His conviction relied heavily on mobile phone data but the European Court of Justice ruled in April that Irish rules on the retention and access by gardaí of mobile data was in breach of European law.

An appeal by Dwyer against his conviction is likely to be heard in the autumn.

Minister for Justice Helen McEntee has said the Government will move to ensure the gardaí do not have “their hands tied behind their backs” and it is expected the legislation will provide for access to mobile data for gardaí where it is required for an investigation.

It is expected the Garda will be able to capture large quantities of mobile phone data in public places and across large areas under the new legislation.

The so-called “quick freeze” of data offers gardaí strong and wide-ranging options to indiscriminately capture data for use as evidence in cases or as an investigative tool.

Under the quick freeze, if a crime was committed at a public event, all the telephone activity in that area could be frozen at the request of the Garda for a defined period, enabling officers to investigate the phone records of suspects.

Mobile phone operators have retained phone data – call, text and location records – for up to two years in Ireland. During the investigation of crime, including minor offences, gardaí were able to secure access to retained data generated on the phones of suspects and other persons of interest.

However, the ECJ ruled this retention of data by mobile phone operators – and gardaí being able to access it – was unlawful.

The new legislation will be designed to enable gardaí to have access to phone records in more tightly restrained circumstances.

Ministers are also likely to approve plans for the Office of Public Works to procure 500 modular units for use by Ukrainian refugees at a number of sites in the State. Most will have two bedrooms, it is understood, and are likely to be ready for use within 16-20 weeks.

Separately, Cabinet is expected to approve plans to extend maternity leave entitlements to county and city councillors. The proposals from Minister of State Peter Burke come in the wake of recommendations from an all-female cross-party group of councillors that examined the issue.

Under the plans, a temporary substitute can be put in place by a councillor taking their full 26-week maternity leave to attend council meetings and vote on their behalf. This arrangement can be extended for a further 14 weeks of unpaid maternity leave time.

Alternatively, councillors can choose to continue to attend meetings but can avail of a special administration payment of €230 per week to pay someone to assist with secretarial work.