AFTER Binyamin Netanyahu's coalition recently shrank from 74 seats to 66 in Israel's 120-seat parliament, he insisted that his government had become stronger. Maybe so. But the opposition has got stronger too, as well as larger. Israelis who bank on peace through negotiation with the Palestinians may have a chance to revive.

The coalition shrinkage was caused by a split in the Labour party, always a restless partner. Labour's leader, Ehud Barak, the minister of defence, quit his party, together with four other members of parliament, setting up a new faction called “Independence”. The reduced Labour party, now numbering just eight parliamentarians, has gone over to the opposition.

The shake-up, as Mr Netanyahu points out, makes his rightist-religious coalition more cohesive ideologically, and thus, he hopes, more disciplined politically. But by consolidating the hawks, the new alignment may also unify and perk up the doves in Israel's aviary. There is a rare flutter of excitement on Israel's left.

Mr Barak's move, excoriated by the Labour rump as opportunistic, is the latest in a series of mergers and secessions that has eroded the old pattern of Israeli politics. For decades a “national camp” comprising the Likud and its allies was pitted against a “peace camp” made up of Labour and like-minded parties, including Israeli-Arab parties. The religious parties were in the middle, inclined to the nationalists but always ready to negotiate with the peaceniks if the parliamentary arithmetic warranted it.

The most cataclysmic of those shifts was in 2005, when the then prime minister, Ariel Sharon, seceded from the Likud to create Kadima, now the largest party in parliament (see chart). This shift had been preceded in the late 1990s by the rise of two new parties: Shinui, an anti-clerical outfit founded by Tommy Lapid, and Yisrael Beitenu, a far-right party, backed mainly by Russian immigrants, led by Avigdor Lieberman. Shinui, a linchpin of Mr Sharon's governments between 2001 and 2006, has since disappeared as swiftly as it arose.

Israel's fluid and fickle party structure reflected a blurring of the old hawk-dove demarcation. The Likud, like Kadima and Labour, purported to support (or at least to acquiesce in) the view that the Israel-Palestine conflict can be solved by creating two sovereign states existing side by side. That was Mr Netanyahu's message to the world after he took office in 2009. His generous disbursement of ministries to Labour was meant to keep onside Mr Barak, a former prime minister in a doveish coalition from 2000-2001, lending credibility to his professed desire to negotiate peace.

But that credibility has been fizzling at home and abroad, since Mr Netanyahu refused to meet the minimal demand of his Palestinian interlocutors (and of Western mediators) that Israel should stop expanding Jewish settlements on the West Bank, the main bit of the Palestinians' would-be state. Labour's break-up may help reclarify the old hawk-dove ornithology. The evolving demarcation is between Israelis who still want, above all, to end the occupation of the Palestinian territories by negotiation or else by unilateral withdrawal, and those (now apparently including Mr Netanyahu) who prefer to stay put, for religious, nationalist or, as many more middle-of-the-road Israelis see it, security reasons.

Could a reconsolidated peace camp win back the middle-of-the-roaders? Tzipi Livni, Kadima's leader, has done well to hold her own ranks together, talking tough on security but consistently arguing for negotiation with the Palestinians. She may pull in some moderate Likud people unhappy with a series of bills before parliament that seem to discriminate against Israeli-Arabs and constrict freedoms. Mr Lieberman, the foreign minister, repulses many in the middle of Israel's spectrum with his verbal assaults on human-rights groups, accusing them of treachery.

Meanwhile there is speculation that a new secular centrist party may emerge before the next election, set for 2012 unless the government falls before then. A popular broadcaster, Yair Lapid, son of the late Shinui leader, is said to be mulling his prospects. The guess is that he would rather align with Kadima than with the Likud. A regrouping of social democrats on Kadima's left flank, with Meretz and Labour to the fore, is also being mooted.

That is the hope of Isaac Herzog, minister of welfare until the recent split, who intends (among several others) to run for the Labour leadership. The scion of a patrician family—his uncle was Abba Eban, a longtime foreign minister, and his father, Chaim, was Israel's president—Mr Herzog says Labour must recover the social democratic values of the party's founding fathers. But would that provide the basis of a ruling coalition on the centre-left with the clout to cut a deal with the Palestinians? That remains a speculation too far.