One of the top Turkish business associations is ramping up its public diplomacy campaign and on Friday urged German Chancellor Friedrich Merz and other European leaders to revive Türkiye's stalled European Union membership process.

"A strong Europe is impossible without Türkiye," the Foreign Economic Relations Board (DEIK) said in a full-page open letter this week in the German newspaper Bild.

That marks the second phase of DEIK's broader initiative timed around Europe Day. The campaign follows similar appeals published in the Financial Times in January.

DEIK says its diplomatic and commercial initiatives aim to re-energize Türkiye's relations with the bloc, including efforts to resolve longstanding visa issues and modernize the customs union agreement.

The board called for a "paradigm shift" after years of stalled accession talks, arguing that Türkiye's integration into the EU's economic security and defense architecture has become a strategic necessity amid challenges including migration, demographic change, the rapid spread of artificial intelligence and the energy transition.

The letter also described Türkiye's full integration as essential for the EU to emerge as a global power, citing what it called Merz's visionary approach at the Munich Security Conference.

It emphasized that the Turkish business community has long been integrated into European value chains and argued that providing a credible path toward EU membership would help restore strategic clarity and mutual trust between Brussels and Ankara.

For decades, Türkiye and the bloc have enjoyed good trade ties and cooperation on migration. However, relations have been strained over multiple issues, including the prolonged process of expansion of the scope of the customs union agreement, maritime issues with Greece and Greek Cyprus, and EU policies on Syrian refugees.

On the other hand, Russia's invasion of Ukraine has pushed the European Union to seek deeper security ties with Türkiye, a NATO ally and long a candidate to join the 27-nation bloc.

DEIK also called on the urgent modernization of the EU-Türkiye Customs Union, saying it is critical to strengthening Europe's competitiveness amid increasing geopolitical fragmentation.

A host of disagreements over recent years have stalled the negotiations for updating the trade agreement. The deeper 1990s-era deal would be expanded to services, farm goods and public procurement. The current deal only covers a limited range of industrial products.

First implemented in 1995, the Türkiye-EU Customs Union has helped boost economic ties. But business groups have long argued that the agreement is outdated and ill-suited for today's trade environment.

Mehmet Ali Yalçındağ, chair of DEIK's Türkiye-Europe Business Council, said the campaign would expand with similar open letters in major newspapers across France, Italy, Belgium and the Netherlands.

"We deem the future of Türkiye-EU relations as not just an economic partnership but a strategic necessity," he said.

Yalçındağ added that the group would continue outreach efforts with universities, civil society organizations and think tanks to promote its vision among stakeholders.