However, although some of the leaders felt that they shared some common ground with the former prime minister of Luxembourg, their overall responses were underwhelming.
Following the S&D group meeting with Juncker, Gianni Pittella, the groups recently elected president, said, "A positive and useful but not yet fully satisfactory meeting. The negotiations are still far from finished.
"I want to thank Mr Juncker for his time and for his sincere answers to the questions we raised during the debate. We found common ground in our discussions, but now words must be translated into concrete proposals for action," he urged.
The Italian deputy continued, "We are glad to know that the next commissioner for economic and monetary affairs will be a member of the socialist and democrat family.
Adding, "This is good news indeed, however, we also call for more clarity and detail on the so-called 'best use' of flexibility instruments set out in the growth and stability pact.
"We are also satisfied with Juncker's commitment to ending the Troikas and replacing them with a more democratic and EU-led approach to tackling the economic and financial crisis."
"A positive and useful but not yet fully satisfactory meeting" - Gianni Pittella
However, Pitella continued, "At the same time, we regret the lack of real action on the urgent problem of immigration, which requires more solidarity among member states. We need - and we continue to call for - a shared European approach to solve a shared European problem.
"We are also far from satisfied with Mr Juncker's remarks on foreign policy: these were too vague to be effective in turning Europe into a political giant and inadequate in responding to complicated and dangerous situations such as those in Ukraine and Syria.
"Finally, we also need more specific proposals on energy and environmental policy, and our group is calling for clear targets to be set," he stressed.
Looking to next week's plenary session is Strasbourg, Pitella said, "Negotiations have just started. We won't stop here.
"The S&D group's final decision on whether to support Juncker has not yet been taken. We will continue our debate next week in Strasbourg ahead of the final vote on Tuesday."
Meanwhile, ECR chair Syed Kamall said that his group "held a good discussion with Mr Juncker" and that "there were many areas where we believe we can work with him if he is confirmed.
“If he seeks to deliver on priorities such as developing a digital single market, pursuing more open trade and promoting energy security, then he will have our support in this work.
“However," the UK deputy continued, "We cannot subscribe to the process that brought Mr Juncker to this point.
"We hope that we are proved wrong but based on the process and this exchange of views, we cannot support Mr Juncker next week" - Syed Kamall
"We believe it represents a shift of power away from the member states and towards the parliament, and that there is a false linkage between people voting primarily for national parties, and the candidates that pan-European parties put forward for the commission presidency," he argued.
“Despite a number of areas of policy convergence we felt that overall we share different views on the future direction of the EU. We hope that we are proved wrong but based on the process and this exchange of views, we cannot support Mr Juncker next week," he concluded.
Elsewhere, Gabi Zimmer, president of parliament's GUE/NGL group, complained, "Juncker's priorities do not match our vision for the EU's future.
"Juncker's priorities do not match our vision for the EU's future" - Gabi ZImmer
She went on, "While he seemed to criticise some of the stifling policies pursued by EU leaders - such as the undemocratic nature of troika - in recent years, he was not willing to abandon it and shied away from proposing a real departure from these failures.
"This is simply not good enough when ending austerity with its devastating impact on millions of citizens is clearly the key challenge of our times," she criticised, adding, "We also sought assurances on the TTIP trade agreement currently being negotiated but were disappointed with the responses received."