LISBON (Reuters) - Portugal's centre-right ruling coalition held a six- to 12-point lead over the main opposition Socialists in four opinion polls as Sunday's national election neared, but remained shy of a margin sufficient to win an outright majority in parliament.
The biggest poll so far in the campaign, carried out by the respected Catolica University and released on Thursday, showed the coalition with 38 percent support against 32 percent for the centre-left Socialists.
Still, the Catolica poll of 3,302 people left the government short of a majority and showed that 15 percent of voters remained undecided. The poll had a margin of error of 1.7 percentage points and was different from the daily tracking polls produced by Catolica.
Another poll, by Marktest put the coalition on 41 percent of voting intentions, well ahead of the Socialists on 28.6 percent.
Other polls have indicated a much tighter race even though the austerity-minded ruling alliance has gained in recent months while the Socialists held steady or slipped somewhat. About one in three voters were still undecided in the Marktest survey.
Given a margin of error of 2.4 percent in the random poll of 1,600 people from Marktest's database, the coalition could get enough votes - that is, close to 44 percent - to secure a majority of seats in the 230-seat parliament, depending on the varying weightings of electoral mandates across Portugal.
The latest daily tracking polls by Catolica University and by Intercampus pollsters gave the coalition 39 percent and 38.4 percent respectively, with the Socialists not far behind on 34 percent and 32.1 percent.
Analysts say the prospect of a weak government and the lack of scope for a broad coalition create political risks that could undermine Portugal's reform efforts and recovery from a debt crisis in the next few years.
Portugal's bailout programme, which it completed in May 2014, has not sparked the major unrest that thrust radical anti-bailout parties into the spotlight in Spain and Greece.
The Communist party remains the country's largest hard left force, with around 10 percent support.
Following are the results of latest opinion polls:
NOTE: PS - Socialist Party; PSD/CDS - centre-right ruling coalition of Social Democrats and rightist CDS-PP; CDU - Communists-Greens alliance. Others - parties without parliament representation, with the leading two - populist PDR and leftist LIVRE - with less than 2 percent support each according to the latest poll. Some include null and void votes in that category.
PS PSD/CDS CDU Left Bloc Others Pollster Date
28.6 41.0 9.3 8.7 3.4 Marktest Sept 30
34.0 39.0 10.0 8.0 5.0 Catolica Sept 30
32.1 38.4 8.4 7.9 3.9 Intercampus Sept 30
33.0 39.0 11.0 8.0 5.0 Catolica Sept 29
31.6 38.8 8.2 7.9 4.0 Intercampus Sept 29
34.0 40.0 10.0 7.0 5.0 Catolica Sept 28
32.1 37.9 9.1 7.5 3.9 Intercampus Sept 28
34.0 41.0 9.0 7.0 5.0 Catolica Sept 27
33.0 38.1 9.0 6.7 4.1 Intercampus Sept 27
43.0 33.0 8.0 7.0 5.0 Catolica Sept 26
32.8 37.5 8.9 6.7 4.5 Intercampus Sept 26
36.0 35.5 10.1 5.0 13.4 Eurosondagem Sept 25
35.0 42.0 8.0 7.0 4.0 Catolica Sept 25
32.3 37.0 9.2 6.1 5.4 Intercampus Sept 25
32.9 37.9 7.8 6.0 4.5 Intercampus Sept 24
35 41.0 9.0 7.0 4.0 Catolica Sept 24
34.1 38.9 8.3 4.8 4.0 Intercampus Sept 23
35.0 40.0 9.0 8.0 4.0 Catolica Sept 23
35.7 38.9 7.3 4.4 4.4 Intercampus Sept 22
34.0 40.0 10.0 8.0 4.0 Catolica Sept 22
37.1 40.1 6.3 4.0 3.5 Intercampus Sept 21
35.0 40.0 8.0 7.0 4.0 Catolica Sept 21
35.0 40.0 8.0 7.0 3.0 Catolica Sept 20
34.0 40.0 8.0 8.0 3.0 Catolica Sept 19
34.0 41.0 7.0 8.0 3.0 Catolica Sept 18
34.7 35.3 8.3 5.8 16.0 Aximage Sept 18
35.5 34.0 10.3 5.2 15.0 Eurosondagem Sept 18
33.3 38.9 8.5 4.6 14.4 Aximage Sept 7
36.0 35.0 10.4 4.6 14.0 Eurosondagem Sept 2
36.3 34.8 10.0 5.0 13.9 Eurosondagem Aug 7
38.0 37.8 7.5 4.0 12.7 Aximage July 17
36.7 34.6 10.2 4.8 13.7 Eurosondagem July 10
37.6 32.7 11.0 6.0 6.0 Intercampus July 9
37.0 38.0 10.0 8.0 7.0 Catolica Univ. June 19
36.9 33.3 10.5 4.5 14.8 Eurosondagem June 12
38 37.2 7.5 4 13.3 Aximage June 4
38.1 33.6 10.3 4.8 13.2 Eurosondagem May 12
37.3 37.2 7.7 4.2 13.6 Aximage May 4
37.5 34.7 10.2 4.3 13.3 Eurosondagem April 15
36.9 36.5 9.2 3.5 13.9 Aximage April 8
(Reporting by Andrei Khalip; Editing by Mark Heinrich)