A new political landscape is emerging in Brazil following the surprise failure of Luiz Inácio Lula da Silva, the president, to win an outright majority in the elections last weekend.

Mr Lula da Silva, of the left-leaning PT, now faces a run-off against Geraldo Alckmin of the centrist PSDB on October 29.

But the election, in which Brazilians also voted for state governors and for federal and state legislators, is already having an impact, suggesting the emergence of a modernising political class and the rejection of traditional pork barrel politics.

“People are voting more sensibly,” says David Fleischer, a political scientist in Brasília. “They seem to be paying more attention to what’s going on and sending a message that they don’t want these types of people representing them any more. It’s a real mandate for change.”

The election was also a striking demonstration of the political polarisation of Brazil between the less developed north and north-east, where people voted overwhelmingly for Mr Lula da Silva, and the rest of the country, where support for Mr Alckmin was surprisingly strong. The divide underlines the appeal to the poor of income transfer programmes such as Bolsa Família, which makes monthly payments of between R$15 ($7, £3.7, €5.5) and R$95 to families with monthly per capita income of less than R$120. The benefits are small but make an enormous difference to those living below the poverty line. (See chart below)

Spending on the Bolsa Família has quadrupled under the Lula government. This year it will transfer R$8.3bn to some 11.1m families. Almost half are in Brazil’s north-east, home to just 27 per cent of the population.

So it was no surprise that Mr Lula da Silva won a landslide in the region. But at the state level, opinion polls indicated that, as in the past, north-easterners would support the centre-right PFL and its allies, especially in the state of Bahia, seen almost as a personal fiefdom for Antonio Carlos Magalhães, the party’s long-time leading cacique or chieftain.

However, Paulo Souto, Mr Magalhães’s protégé, was beaten in a shock result by Jacques Wagner, a progressive on the reforming wing of Mr Lula da Silva’s PT. And next door in Sergipe, Marcelo Déda, another PT reformer, also swept home against his PFL challenger.

Both were certainly helped by the Bolsa Família. But other reforming candidates did well around the country. Yeda Crusius of Mr Alckmin’s PSDB was the surprise leader in the southernmost state of Rio Grande do Sul and goes into the second round on October 29 (to be held for president and the 10 out of 27 state governorships that were not decided on Sunday) against Olívio Dutra of the PT. Denise Frossard, a moderniser in the centre-left PPS, will put up a strong challenge to Sérgio Cabral of the catch-all PMDB for the governorship of Rio de Janeiro.

In elections for one-third of the 81 senate seats, reformers also did well around the country, while some of the old guard were swept away (although former president Fernando Collor, impeached for corruption in 1992, returns to Brasília as a senator for Alagoas – a sign of the enduring power of some local caciques).

Ricardo Ismael, a political scientist in Rio de Janeiro, says: “Brazil has a recent history of politicians who will support the military, the right, or the left – whoever is in power. Now we are seeing the emergence of a generation of politicians who are more concerned with defending the public good.”

The event that did most to erode Mr Lula da Silva’s earlier commanding lead in opinion polls was an attempt by leaders of the PT to implicate José Serra, the PSDB’s victorious candidate for governor of São Paulo state, in a corruption scandal known as the bloodsucker scheme. It also reminded voters of the previous wave of corruption scandals that rocked the government for most of last year.

Voters expressed their disapproval not only by voting for Mr Alckmin but by rejecting politicians accused of involvement in the bloodsucker scheme. Of 50 who ran for office, mostly for federal deputy, just five were elected.

That modernisers may be in the ascendant can also be seen in the public row that has developed since Sunday within the PT. The party’s old guard – especially those in its traditional heartland of São Paulo who were involved in the botched attempt to smear Mr Serra – have come under fierce attack. Mr Déda, the re-elected PT governor of Sergipe, says: “The São Paulo PT used to be the party’s heart and brains but now it is the intestine, with a bad case of diarrhoea.”

It is not yet clear, however, which forces will dominate Congress from next year. That depends on who wins the presidential run-off, and how congressional alliances are formed as a result. Even with the rise of the modernisers, this is sure to involve some old-fashioned horse trading.