François Fillon of The Republicans (LR)—after winning the party's first open primary—and Le Pen of the National Front led first-round opinion polls in November 2016 and mid-January 2017.

After strong debate performances, Jean-Luc Mélenchon of La France Insoumise (FI) rose significantly in polls in late March, overtaking Hamon to place just below Fillon.

Her campaign programme prioritised the national interests of France and an exit from the eurozone,[17] emphasising her party's traditional concern about security and immigration, as well as socioeconomic issues and the sovereignty of the French state, on matters of currency, borders, the economy and rule of law.

He proposed to end family reunifications and reform the right to birthright citizenship, halt the flow of economic migrants, and increase residence requirements to secure French nationality.

[61] Juppé also demanded transparency on the funding of places of worship, civic training for imams, and, unlike Sarkozy, favored allowing women to wear the Muslim headscarf at universities.

Like the other primary candidates, he planned to eliminate the wealth tax; in addition, Fillon suggested abolishing the 35-hour workweek – capping it at the 48-hour maximum allowed within the EU – and the implementation of other liberal economic measures.

His announcement reflected his high personal unpopularity and resentment among Socialist colleagues regarding remarks he made about cabinet members and other associates in the book Un président ne devrait pas dire ça... (A president should not say that...) by Gérard Davet and Fabrice Lhomme, journalists at Le Monde.

[80] On 17 December, the High Authority declared that seven candidates qualified to appear on the ballot: four from the Socialist Party – former Prime Minister Manuel Valls, Arnaud Montebourg, Benoît Hamon, and Vincent Peillon – and François de Rugy of the PE, Sylvia Pinel of the PRG, and Jean-Luc Bennahmias of the PD.

[82] Shortly after declaring his candidacy on 5 December, Valls proposed to abolish article 49.3 of the French constitution, a procedure that allows bypassing legislative approval, in a "democratic renaissance"; as Prime Minister, he invoked it on six occasions, using it to pass the Macron and El Khomri laws.

[83] He also proposed a 2.5% increase in public spending while keeping the budget deficit under 3%, guaranteeing a "decent income" of €800, reducing the gender pay gap by half, pausing the enlargement of the European Union, appending a charter of secularism to the Constitution, consolidating the nuclear industry, and mandating six months of civic service.

[87] Former Minister of the Economy Arnaud Montebourg, a Socialist rebel known for promoting "made in France", presented a firmly left-wing project shortly after declaring his candidacy in August 2016.

[88] He also proposed €30 billion in spending to stimulate economic growth, lower the general social contribution (CSG) to increase individuals' purchasing power by €800 a year, create 5,000 new posts in hospitals, call a referendum on a new republic, promulgate a law on the separation of banking activities (as Hollande did), impose a European carbon tax, and establish a national anti-terrorism prosecutor.

Like fellow Socialist dissidents, Hamon criticized the El Khomri labor law and promised to repeal it if elected, and suggested that it be replaced with legislation acknowledging the need for greater social protections, including the right to disconnect and recognizing burnout as an occupational disease.

[102] On 25 January 2017, the satirical weekly Le Canard enchaîné first alleged that François Fillon employed his wife Penelope as his parliamentary assistant from 1998 and 2002 and for six months in 2012, with no evidence that she completed any substantial work.

[104] On 26 January, François Fillon appeared on TF1 to respond to these allegations, stating that his wife had "edited my speeches" and "stood in for me at events when I couldn’t be there", also claiming that the reason that she was never seen working in the Palais Bourbon was because "she was never on the front line".

[106] Interrogated by investigators the same day, former editor-in-chief of the Revue des deux Mondes Michel Crépu claimed that only "two or maybe three" bylines in the review were attributed to her, also saying that he had seen "no trace" of any work by her that would "resemble [that of] a literary adviser".

[108] Video excerpts of a May 2007 Sunday Telegraph interview with Penelope Fillon surfaced on 2 February, in which she claimed that she had "never been his assistant", referring to her husband; The footage aired on Envoyé spécial on France 2 that evening.

[111] On 6 February, Fillon held a press conference at which he "apologized to the French people" and acknowledged that he had committed an "error" in employing family members as parliamentary assistants, but appended that he "never broke the law".

The satirical weekly also asserted that she received a double salary during the summer of 2002, as she was hired by Joulaud's office on 13 July, more than a month before her contract as a parliamentary assistant with her husband expired, on 21 August.

An article in the same issue reported that Marie Fillon was simultaneously employed as a parliamentary assistant while training to become a lawyer, taking the first post in October 2005 and entering the EFB in January 2006.

Fillon responded to the claims in a press release by saying that Le Canard enchaîné conflated the amount his wife collected in November 2013 with reported earnings in August 2007 after the conclusion of her work with Joulaud,[113] and denounced the paper's allegations as "lies".

With a "political committee" planned for the following day, he proposed to assemble a modified campaign team, naming François Baroin, Éric Ciotti, and Luc Chatel, in an attempt to rally support around his candidacy.

[128] The same day, Le Canard enchaîné revealed that Fillon had failed to declare to the HATVP a €50,000 loan from Marc Ladreit de Lacharrière, president of the Revue des deux Mondes.

In particular, the probe sought to determine whether documents seized during a search of the National Assembly in March were forged in order to corroborate the veracity of Penelope Fillon's work as a parliamentary assistant.

[143] Seeking to put aside the controversy in a meeting in Toulon on 18 February, he attempted to qualify his remarks, saying that he was "sorry" for having "hurt" and "offended" many as a result, but nevertheless continued to insist on acknowledging that France had a responsibility for its colonial past, not just in Algeria.

[157] In an interview with Associated Press the head of the French government's cyber security agency, which investigated leaks from President Emmanuel Macron's election campaign, said that they didn't find any trace of a notorious Russian hacking group behind the attack.

[8] A debate between François Fillon, Benoît Hamon, Marine Le Pen, Emmanuel Macron, and Jean-Luc Mélenchon took place on 20 March, hosted by TF1 and moderated by journalists Anne-Claire Coudray and Gilles Bouleau.

The choice of date meant that TF1 would not be required to provide candidates with equal speaking time, as Conseil supérieur de l'audiovisuel (CSA) regulations do not go into force until 9 April, the start of the official campaign.

[169] BFM TV and CNews hosted the second debate on 4 April at 20:40 CEST, moderated by Ruth Elkrief and Laurence Ferrari,[170] inviting all candidates who qualified to appear on the first-round ballot.

Numerama, an online publication focusing on digital life, described the leaked material as "utterly mundane", consisting of "the contents of a hard drive and several emails of co-workers and En Marche political officials."