Portugal's ruling alliance well in lead for Sunday election - poll

The survey by Marktest pollsters, who usually track market trends, put the coalition on 41 percent of voting intentions, well ahead of the Socialists, on 28.6 percent.

However, other polls have indicated a much tighter race even though the austerity-minded ruling alliance has gained in recent months while the centre-left 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 mass resistance 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)