The lead candidates in next month's European Parliament election have taken swipes at each other over accusations of tolerating undemocratic behavior within their political families.

Manfred Weber of the European People's Party (EPP) and Frans Timmermans of the Socialists and Democrats (S&D) say they have distanced themselves from controversial parties in their groups — and both claim they've done so more effectively than their rival.

Ahead of the election in late May, the EPP suspended Hungary’s ruling Fidesz party, while the S&D froze relations with Romania’s ruling Social Democratic Party (PSD). Critics say that the two parties have presided over democratic backsliding in their countries.

But in interviews with POLITICO and television channel ARTE last week, Weber and Timmermans pointed the finger at one another for not doing enough to combat rule-of-law problems within their party families.

Weber, the EPP lead candidate to head the next European Commission, said that he was prepared to expel Hungarian Prime Minister Viktor Orbán’s Fidesz altogether following the conclusion of an ongoing inquiry.

Timmermans highlighted his own party’s decision to freeze cooperation with Romania’s ruling party.

Orbán had stopped compromising, Weber said, adding that this “is for me unacceptable.” He continued: “We will expel if there is no change."

But the Bavarian politician was quick to point out that other countries, led by non-EPP governments, have also experienced rule-of-law challenges.

“I see we have a bigger problem in Europe. Viktor Orbán is one question, but we have Romania, we have Slovakia, we have Poland, we have a lot of countries in the European Union where we have concerns,” Weber said, while noting that he and his party voted in favor of activating a rule-of-law sanctions mechanism against Hungary.

“I take my responsibility in my camp, and others must do the same," he said.

Timmermans similarly highlighted his own party’s decision to freeze cooperation with Romania’s ruling party.

The Socialist candidate said that he had been “politically color-blind” as Commission vice president and had been “just as strict with Poland, Hungary, and Romania.”

He also took a swipe at Weber’s party, which suspended Fidesz more than five years after the European Parliament first raised concerns about the state of the rule of law in Hungary, saying: “My political family will not take years to take action against a government that doesn’t behave.”

On migration, the two candidates took a broadly similar approach.

Timmermans said that the EU had to demonstrate that it was able to control migration, adding: “This begins with stronger border controls, but it ends with European asylum policy, that we have the same procedures so that you don’t go asylum-shopping in the European Union. And that we have the same humanitarian approach, that real refugees get real protection in Europe, and that people who don’t deserve to be in Europe get sent back to the countries of origin.”

Weber, who said that migration should be the "top issue" for the next Commission president, echoed the idea of striking a balance between tougher controls and humanitarian considerations.

While calling for “strict border control,” the EPP candidate also talked about the need for “resettlement," referring to Pope Francis’ message of humanitarian responsibility.

Weber and Timmermans were answering questions as part of a series of pre-election interviews with candidates for the post of Commission president. Other interviewees included the European Conservatives and Reformists' Jan Zahradil, the Greens' Bas Eickhout, the Liberals' Margrethe Vestager, and the European Left's Violeta Tomić.

But not all candidates are focused on the presidency itself. Vestager, who currently serves as commissioner for competition, said that she would prefer to stay in her current role.

“I would very much like to continue as a commissioner, because in my field we are in the middle of something, I think we can do a lot more to serve Europeans even better," she said, adding that "this would be my first choice."