United Kingdom

General information about the policy process
The United Kingdom of Great Britain and Northern Ireland (UK) joined the European Union (EU) on 1 January 1973. The UK elects 73 Members of the European Parliament (MEPs), and contributes to the European Commission as a full member of the European Union. Since the UK voted to leave the EU in a referendum on 23 June 2016, the nation decided not to take up its 6-month presidency of the Council. This, and other consequences of the "Brexit" vote such as marginalisation of the UK at leaders' meetings, may have weakened UK policy making power leading up to its departure from the EU. However, EU law will continue to apply in the UK until 31 December 2020, the end of the implementation period defined in the Withdrawal Agreement.

Transposing EU law
The UK recognises the supremacy (or primacy) or European law over domestic law, allowing the national parliament at Westminster to transpose EU policy. On 15th December 2010, the government announced Guiding Principles for EU Legislation, which states what policy makers and lawyers across the government need to do to implement EU legislation. They are in place to ensure that the UK uses a systematic approach to transposition to minimise the burden on UK businesses to ensure they are not at a disadvantage to their European competitors. In 2018 the UK government updated its Transposition guidance on how to implement European Directives effectively. According to this, government should use copy-out for the transposition of EU policy whenever possible, except for when this negatively impacts UK interests. Guidelines have been in place to prevent 'gold-plating' practices to ensure smooth transposition of EU law since 2013, when the UK updated its guidance on transposition.

National actors involved
England, Scotland, Wales and Northern Ireland are represented in the national parliament at Westminster in London. The national parliament is responsible for the transposition of EU law and directives into domestic law. As the national parliament is responsible for the foreign affairs of the different regions, EU directives and regulations are transposed by this parliament on behalf of the regional governments.

The parliament can be advised on implementation by national or government bodies such as Public Health England, which compile reports reviewing areas of interest, identifying problems within that area, and offering solutions.

Trade Unions and other non-governmental organisations and lobbying groups can also influence national decision making.

Regional and local actors involved
Scotland, Wales and Northern Ireland have their own legislative bodies for domestic law. These bodies may have EU legislation transposed into their law via the national Parliament through various Acts  or, if the EU legislation concerns devolved matters, the devolved administrations have the competence to transpose the legislation. Furthermore, while the national Parliament has adopted a policy of 'copying out' in transposition of EU legislation into national law, Scotland has explicitly not done so, which may lead to divergence in transposition of EU legislation within the UK.

In 2011, the Localism Act was introduced by Parliament aiming to facilitate the devolution of decision-making powers to councils and local communities in England. In this sense, the Localism Act has enabled local authorities to do anything provided they do not infringe the law. This act lays down provisions on important issues for communities such as housing, public procurement, local taxes, etc. Additionally, local authorities also have some responsibility for the implementation of EU laws and directives. For example, air quality standards must be organised on the council level and measure to reduce pollutants can be enacted through the council with local by-laws (e.g. the congestion charge brought on vehicles travelling through key zones in London was adopted by the Greater London Authority in 2003). Equally, the national government can pass down to local authorities any fines imposed by failure to comply with EU legislation.

Recent devolution deals, and local referenda have created a number of metro-mayors. Areas such as Bristol, West-Midlands, Tees Valley, Greater Manchester and Merseyside have been granted significant, but varied policy powers. However, their fiscal powers are limited.

More significant devolution has been attempted in England. In 2004 a referendum for a regional assembly for the North East was called, however, the public voted 77.93% against it. The assembly would have had some legal powers and be responsible for things such as clean air and the environment, which could have possibly meant transposition of EU directives would have been necessary.

Air quality policy
Air quality is a devolved matter, meaning that decision-making has been delegated to devolved institutions (e.g. Welsh Parliament).

In 2015, the Supreme Court ruled that the UK government was in breach of Article 13 of the Air Quality Framework Directive 2008/50/EC. As a consequence, the UK now has an Air quality plan for nitrogen (NO2) in UK (2017). Compliance with the pollutant values set out in Directive 2008/50/ec is assessed by the Department for Environment, Food and Rural Affairs on an annual basis.