The DUP is on course to regain the East Belfast seat in the Westminster election in May, a major Belfast Telegraph survey has revealed.

But the results of our exclusive poll show that all is still to play for, with the Alliance Party close enough to suggest that a repeat of its 2010 electoral shock is still possible.

The survey, carried out by LucidTalk, our polling partners, continues our series focusing on east Belfast. Since the Alliance's Naomi Long toppled DUP leader Peter Robinson, the tussle for power in the east of the city has been fierce.

Now our opinion poll has revealed that DUP candidate Gavin Robinson is polling 21.2%, compared to Mrs Long's 17.7%, including don't knows and non-voters.

When the don't knows and non-voters are excluded, the gap stretches to 34.4% for DUP and 28.7% for Alliance.

But the survey contains a sting in the tail for the DUP. It shows that leader Peter Robinson would be less likely to win the seat than the new candidate Gavin Robinson.

A number of voters thought, mistakenly, that Peter and Gavin Robinson were related. "We don't want another Robinson family member as our MP," one former DUP voter told our pollsters.

Another significant finding was that a number of constituents who voted Alliance last time said they felt let down by Naomi Long's stance on the Union flag. Some respondents felt she should have been more vocal over the issue of the flag being removed from the City Hall and were confused by her stance.

A separate question showed that people across the east are deeply disillusioned about the peace process, with many believing that nationalists have got the best deal. Less than 6% said they felt unionists had fared better.

The outcome of the east Belfast Westminster poll will depend to some extent on which other parties stand in the crowded unionist field.

Our survey shows that, including don't knows and non-voters, the UUP will poll 9%, the PUP 4% and the TUV 1.7%.

According to Bill White, head of LucidTalk, Alliance may gain support before the election because Ms Long is the sitting MP and that often happens in the final weeks of a campaign.

He believes that, although the DUP's Gavin Robinson is the favourite, he would really need another 6% at this stage to be sure of victory and overcome Ms Long's 'incumbency factor'.

The opposite argument is that the incumbency factor could work for the DUP because, as the largest party who have held the seat for several elections, they may acutally be looked on as the incumbents.

What the DUP really needs is other unionist parties, particularly the UUP or PUP, to stand aside.

The DUP has sounded out the UUP on this but there is no deal so far and any agreement would probably depend on some wider pact taking in other marginal seats, perhaps giving the UUP a free run in South Belfast.

As Mr White put it: "The DUP can't really afford to have the 'whole rake' of unionist parties running against them. This poll shows they would still probably win, but it's getting a bit risky."

It would be riskier still with Peter Robinson as the candidate. Over a quarter of those who said they intended voting DUP (29.3% of the party's declared support) said they would be less likely to vote for the party if Peter Robinson, not Gavin, was the candidate.

Naomi Long had an unexpected victory in 2010 - her vote was up 26.1% on her previous performance - but Alliance's East Belfast vote fell back to an estimated 18% to 22% in last year's local government and European elections.

It will be hard for Ms Long to repeat her 2010 performance, especially with other centrist parties like the Greens (who are fielding their councillor Ross Brown) and the Tories in the race.

Our final question asked if on balance the Protestant/unionist community or the Catholic/nationalist community had done better out of the peace process.

Two-thirds of those asked believed that Catholics had come out on top, with a majority across all social groups.

MP Long may yet hold on if party can get core voters out

Who wins East Belfast in this year's general election could come down to how strongly Alliance polls in two key areas.

The DUP has a narrow poll lead as it seeks to take back the seat from Naomi Long.

Geographical analysis shows the Alliance vote is strongest in middle-class parts of the constituency.

In the Gilnahirk, Cherryvalley, Tullycarnet and Knock area, Alliance has 30.4% of the vote with the DUP trailing on 15.2%.

Alliance is also polling strongly in Ballyhackamore, Belmont and Stormont, with 24.1% of Alliance voters coming from there, compared to 11.5% for the DUP.

Alliance needs to get its vote out in these two areas - and score well - otherwise the DUP is odds-on to win back the seat.

That is because the DUP is ahead in the four other areas in the constituency, most markedly in Dundonald, Carrowreagh and Ballyhanwood, where it leads Alliance by 20.7% to 9.7%.

There is also an interesting gender aspect to party support.

Alliance gets proprotionally higher backing from women, but this is countered by the strong support the DUP gets from men.

Of the female poll respondents, 21.1% said they would vote Alliance, compared with only 16% saying they would vote DUP.

By contrast, of the male respondents, 27.2% said they were going to vote DUP, compared with only 13.8% for Alliance.

Non-voting figures could also have a role to play.

The Dundonald, Carrowreagh and Ballyhanwood area - which is primarily loyalist working class - had 42% saying they wouldn't vote.

By contrast the Gilnahirk, Cherryvalley, Tullycarnet and Knock area - where Alliance is ahead - only has a third (33.3%) saying they wouldn't vote.

In 2010 Naomi Long added 9,000 votes to her 2005 tally to take East Belfast from the DUP by a 1,533 majority.

One of the key reasons for some of that support seeping away is likely to be the flags issue.

One respondent, who said they intended to switch from Alliance to the DUP come May, said: "I voted Alliance the last time because of the Peter Robinson effect, but not this time because they let us down on the flags issue."

A UUP voter said they would back Alliance if the party clarified its position on flags.

However, Naomi Long has gained a reputation for being a hard-working MP.

Today's Belfast Telegraph/LucidTalk poll suggests Alliance's share of the vote has improved compared to its performance in East Belfast in last year's local government election.

Last May Alliance had a share of the vote estimated at between 18 and 22%, although this is difficult to precisely measure because of overlapping boundaries.

Excluding don't knows, 28.7% said they would back Alliance in East Belfast at the Westminster poll.

One problem for the DUP could be a split vote if the UUP, PUP, Ukip and TUV all run in East Belfast.

East background

East is a series which matters to people right across Northern Ireland. Since 2010, when Alliance’s Naomi Long ousted DUP leader Peter Robinson, the battle for the east Belfast seat at Westminster has rarely been far from the headlines. The tussle for power has been one of the fiercest in Northern Ireland and in May’s general election it will be the result many people look to first. The key issues in the east have become emblematic of the cut and thrust of politics across Northern Ireland as the DUP seeks ways to respond to the loss of one of its heartlands. That means what happens in the east affects us all. All this week the Belfast Telegraph is focusing on this key battleground of the election. We’ll be looking at the issues, talking to people on the ground, and crucially, publishing an exclusive opinion poll on which way the seat might go.

Methodology: How the questions were asked and the figures compiled

Polling was carried out by LucidTalk over the period January 12-28, 2015.

820 completed opinions were obtained within the targeted demographic area of the parliamentary constituency of East Belfast. All respondents, were aged 18+, and were interviewed by telephone (approximately 90%) or directly face-to-face (approximately 10%).

All data results produced are accurate to a margin of error of +/-2.6%, at 95% confidence. All reported margins of sampling error will include the computed design effects for weighting. In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.

LucidTalk is a member of all recognised professional polling and market research organisations, including the UK Market Research Society (UK-MRS), the British Polling Council (BPC), and ESOMAR (European Society of Market Research organisations). The BPC is the primary UK professional body ensuring professional polling and market research standards.

All polling, research, sampling, methodologies used, market research projects and results, and reports production are, have been, and will be carried out to the professional standards laid down by the BPC.

For full results, including methodology, full demographic analyses and technical commentary, click here

Belfast Telegraph