The euro was on track for its biggest weekly fall against the dollar in two months on Friday on concerns that a new government will worsen French fiscal situation as a snap parliamentary election approaches.

The yen hit a six-week low against the dollar, before rebounding, after the Bank of Japan (BOJ) surprised markets with a dovish monetary policy update. French markets endured another brutal sell-off as political uncertainty unleashed the biggest weekly jump in the premium investors demand to hold French government debt since 2011, and bank stocks tumbled.

“On both ends of the French political spectrum, the parties that are campaigning are fiscally expansionist parties,” said Karl Schamotta, chief market strategist at Corpay in Toronto. “Markets are mostly responding to additional fiscal stress.” French Finance Minister Bruno Le Maire said on Friday that the euro zone's second-biggest economy was at risk of a financial crisis if either the far right or left won because of their heavy spending plans.

Marine Le Pen's eurosceptic National Rally (RN) is leading in opinion polls following President Emmanuel Macron's surprise decision last Sunday to call a snap election.

The euro is on track for a 1.2% weekly fall - its biggest since April - and was last down 0.61% on the day at $1.0668, the lowest since May 1.

The euro's weakness has helped drive the dollar higher. The dollar index - which tracks the currency against six peers - was up 0.52% at 105.78, the highest since May 2.

“We're seeing flows into the U.S. on both ends of the spectrum - from the safe-haven side as well as on the yield-seeking side - given that U.S. yields remain well above those available elsewhere,” said Schamotta.

The European Central Bank and Bank of Canada have begun cutting rates while the Federal Reserve holds steady. The U.S. central bank adopted a more hawkish than expected tone at this week’s meeting when Fed officials projected only one rate cut this year and pushed out the start of rate cuts to perhaps as late as December.

The yen fell after the BOJ's decision to hold interest rates and restart bond buying. In a surprise for markets, the BOJ said it would continue to buy government bonds at the current pace for now and lay out details of its tapering plan at its July policy meeting.

BOJ governor Kazuo Ueda said the central bank was "paying close attention" to the impact of the weak yen on inflation, and added that a rate hike in July was a possibility, depending on economic data.

The dollar was last up 0.15% at 157.26 yen, after earlier reaching 158.26, the highest since April 29.

The yen's decline to a 34-year low of 160.245 per dollar at the end of April triggered several rounds of official Japanese intervention totaling 9.79 trillion yen ($62 billion).

In cryptocurrencies, bitcoin gained 0.52% to $67,031.

(Reporting By Karen Brettell; Editing by Kevin Liffey)