The Taoiseach will meet other EU leaders on Thursday for the second time in a fortnight to try to bring down energy prices, though persistent divisions between them mean the bloc is unlikely for now put a ceiling on what it pays for gas.
The 27 countries are expected to back an alternative price benchmark for liquefied natural gas and joint gas buying, after earlier agreeing to cut consumption and introduce levies on windfall profits in the energy industry.
But they remain as split as they were months ago on whether and how to cap gas prices to stem high inflation and stave off recession, after Russia cut gas flows following its invasion of Ukraine.
While 15 countries including France and Poland push some form of a cap, they face strong opposition from Germany and the Netherlands – respectively Europe's biggest economy and gas buyer, and a major European gas trading hub.
"An agreement is extremely unlikely... Opinions seem to be really far apart," a senior EU diplomat said ahead of Thursday's talks.
Speaking ahead of the meeting, Micheál Martin said leaders would discuss "the continuing energy crisis, in particular our efforts to ensure security of supply, and to mitigate the impact of high energy on households and businesses across the EU."
The Taoiseach said the European Commission's proposals would "need careful consideration".
"The only certain path to energy security and sustainable prices is to accelerate the green transition – boosting investment in future-ready energy infrastructure, increasing interconnection and rolling out innovative renewable technologies," he added.
The leaders also discuss emergency spending to mitigate the effects the acute energy crunch has on their economies and 450 million citizens.
While some countries have called for the bloc to issue new joint debt to finance that, more frugal members say hundreds of billions of euros unused from previous programmes should be spent first.
Another disagreement is whether to provide immediate relief through direct subsidies to households and businesses, or invest in green energy that would make the bloc more resilient in the future.
"Division is not a luxury we can afford," the summit's chairman, European Council President Charles Michel, said.
But given EU countries' diverse energy mix and interests, the meeting risks falling short on concrete action, with other concerns being whether a gas cap would enable Britain to buy cheaper energy or compromise stability of supplies.
"Unity among member states is dangerously under pressure, with unilateral national decisions being announced without an EU framework to keep them together," said E3G, a think-tank dedicated to climate change transition.
"This fragmentation ...could undermine the credibility of the EU's response."
EU energy ministers meet again next week but another senior EU diplomat said they did not expect more detailed decisions before November.
War in Ukraine
EU leaders will also discuss options for giving more support to Ukraine, including providing energy equipment, helping restore power supply and long-term financing to eventually rebuild the country.
As regards bringing those responsible for alleged war crimes in Ukraine to justice, some EU countries want to set up a dedicated tribunal quickly, while others are seeking to go more slowly to ensure maximum international endorsement.
"The European Council condemns in the strongest possible terms the recent indiscriminate Russian missile and drone attacks targeting civilians and civilian objects and infrastructure in Kyiv and across Ukraine," the leaders will say, according to their draft statement.
They will single out Belarus for enabling Russia's war but are not expected to support further sanctions against Moscow on Thursday.
The bloc is already moving to impose new sanctions on Iran over the use of Iranian-made drones in Russian strikes on Ukraine.
