Former Chancellor Helmut Kohl's political party, the Christian Democrats (CDU) narrowly escaped political embarrassment after his second wife, Maike Kohl-Richter, reportedly tried and failed to prevent his one-time protégé, Chancellor Angela Merkel from speaking at the statesman's memorial service, according to the German magazine Der Spiegel.

In addition to being Chancellor, Merkel is also the current leader of the CDU - two titles once also held by Kohl.

Instead of having a state funeral, Kohl will become the first person to be honored with a European memorial service on July 1.

The unique service will be held in recognition of his efforts to unite Europe, chiefly the feat of achieving the German reunification, as well as for his push for greater integration within the European Union.

Despite Kohl's widow's objection, Merkel was confirmed as speaking at the service as a speaker, along with European Commission President Jean-Claude Juncker, French President Emmanuel Macron and former US president Bill Clinton.

The memorial in Strasbourg is later to be followed by a funeral in the Catholic cathedral in Speyer, a city on the Rhine River and the burial site of historic European personalities, near Kohl's home of Ludwigshafen.

Read more: Opinion: A Funeral fit for Pharaoh Kohl

Fall from grace

Kohl had grown estranged from Merkel since retiring from politics in 2002. He never forgave her for effectively forcing him to quit politics after he had been implicated in an elaborate party financing scandal in 1999 involving anonymous donations, which are illegal under German law.

Although the affair never tarnished his legacy as the architect of German reunification, Kohl distanced himself in his final years from many of his erstwhile political allies on account of their campaign against him.

Known for holding on to grudges, Kohl reportedly rejected the idea of having Merkel speak at his funeral, according to his widow. He furthermore stated that he did not want to be given a state funeral.

While the idea of honoring him with a European funeral is seen to be in agreement with his wishes, Kohl's widow seemed to have only reluctantly agreed to have Chancellor Merkel speak at the memorial in Strasbourg after voicing her objection on the issue.

The Orban controversy

Kohl's widow Maike Kohl-Richter, who is 34 years his junior, said that instead of Merkel, Kohl had wanted to have Hungarian Prime Minister Viktor Orban speak at the memorial. Orban had been mentored by Kohl in the early years after the 1989 collapse of East European Communism, espousing liberal ideas as a young politician at the time. Later they became lifelong friends.

However, as prime minister of Hungary Orban has been criticized for steering an authoritarian course in his country - one that is seen to be at odds with Kohl's legacy.

With his anti-EU stance and rejection of refugees coming to Europe, Orban will not be invited to hold a speech at the event.

There has been no comment on whether Orban will be attending the funeral. He did, however, send a letter to Kohl-Richter, in which he reportedly lauded Kohl's work as a "compass" to follow.

Family feud

Kohl-Richter has also reportedly clashed with his estranged son Walter, who said that he had been barred from visiting the couple's home earlier in the week to discuss funeral arrangements. The claim was later denied by her lawyer.

Walter Kohl said he only learnt of his father's death from the radio, having last spoken to him, by telephone, in 2011.

Kohl sons Walter and Peter are among a number of people who say that his second wife had isolated him. Kohl had married Maike Kohl-Richter in 2008 - seven years after his first wife Hannelore's suicide.

Bundestag speech

Meanwhile German Parliament President Norbert Lammert said during a eulogy at the Bundestag in Berlin that Kohl's "polarizing" character had served as the "personified confidence-building measure" people were looking for in 1989 as calls for reunification rang out in East Germany and West Germany.

Lammert added the former chancellor's death also marked a "deep severing" of Germany's present-day population from its past generations of leaders, such as Konrad Adenauer, Willy Brandt and Kohl.

Lammert also recounted Kohl's rhetorical abrasiveness, including hefty verbal exchanges with the late Social Democratic Party former Chancellor Helmut Schmidt, whom Kohl beat in 1982, and Kohl's emergence as a young parliamentarian in his Rhineland-Palatinate home state in the 1960s. 

Current German President Frank-Walter Steinmeier, and former presidents Joachim Gauck and Horst Köhler, also attended the ceremony.