Natural Gas and Liquefied Natural Gas (LNG) play a dominant role in the European energy mix; significantly contributing to the supply security and the transition from heavy fossil fuels to Renewable Energy Sources (RES). For these reasons, the establishment of a fully liberalized, competitive, and secure Single Gas Market within the framework of the Internal Energy Market has been a primary goal of European legislation. 

Directive 2009/73/EC and Regulation (EC) 715/2009, repealing Directive 2003/55/EC and Regulation (EC) 1775/2005, respectively, establish the general regulatory framework for the development of the Single Gas Market. Specifically, Directive 2009/73/EC encompasses common rules regarding the transmission, distribution, supply, and storage of natural gas, aiming to provide non-discriminatory market access for all market players. Regulation (EC) 715/2009 sets rules concerning access to natural gas transmission networks, simultaneously creating the European Network of Transmission System Operators for Gas (ENTSOG), which, along with the Agency for the Cooperation of Energy Regulators (ACER), which are jointly responsible for drafting the Network Codes.  

The Network Codes for natural gas (Regulations (EU) 2014/312, 2015/703, 2017/460, 2017/459) constitute sets of rules aiming to ensure the efficient interconnection of individual markets and transmission networks, with the goal of completing the internal gas market. 

However, the goals of the European Green Deal, aiming for complete climate neutrality by 2050 and an intermediate goal of 55% emissions reduction by 2030, necessitate the abandonment of fossil fuels and the transition towards clean energy. Therefore, the legislative measures within the "Fit for 55" package focus on energy production from RES, energy efficiency, and the decarbonization of the Gas Market by promoting renewable gaseous fuels such as Green Hydrogen, gradually replacing natural gas in the entire transmission network. 

The increase in energy prices and the reduction in natural gas supply due to the global energy crisis following the COVID-19 pandemic and the Russian invasion of Ukraine present challenges for Europe, highlighting the issue of the Union’s dependence on gas imports and its limited strategic reserves. Consequently, supply security and the detachment from Russian natural gas imports are central to the goals of the Single Gas Market. 

Based on these objectives, the REPowerEU plan launched in May 2022, aiming for an immediate reduction in dependence on Russian Natural Gas, leads to measures such as Regulation (EU) 2022/1032, amending Regulations (EU) 2017/1938 and (EC) No 715/2009 regarding gas storage, Regulation (EU) 2022/2576 to strengthen solidarity through better coordination of gas markets, reliable reference indicators for prices, and cross-border gas exchanges, and as well as, Regulation (EU) 2022/1369, concerning coordinated measures to reduce gas demand.