MANILA - Opposition slate Otso Diretso on Tuesday remained optimistic that it could still pull a "come from behind, surprise victory" after a recent pre-election survey showed only 1 out of its 8 senatorial aspirants had a statistical chance of winning in the May midterm elections.

Reelectionist Sen. Bam Aquino was the lone Otso Diretso candidate who was on the list of hypothetical election winners based Pulse Asia's survey conducted from April 10-14.

The slate's 7 other bets - Magdalo Rep. Gary Alejano, lawyers Chel Diokno, Romulo Macalintal and Florin Hilbay, civic leader Samira Gutoc and former lawmakers Mar Roxas and Erin Tañada - ranked between the 14th and 43rd slots.

• Pulse Asia April 2019 survey: Top 15 senatorial preferences

"Ang pinakamahalagang survey ay ‘yung araw ng halalan," Otso Diretso campaign manager Sen. Francis Pangilinan said in a television interview.

(The most important survey is the one held on election day.)

"At sa aking labing-walong taon bilang senador, ilang eleksyon na rin ang nadaanan natin bilang campaign manager at bilang kandidato, nakita natin may mga pangyayari na sa huling dalawang linggo ng eleksyon, ‘yung mga nasa labas ng top 12 pagdating ng araw ng halalan ay ‘come from behind’ ika nga at naipapanalo nila. Surprise victory ika nga," he said.

(In my 18 years as a senator and my experience as a campaign manager and a candidate, we saw that there were instances wherein those who are not in the top 12 2 weeks before the elections would suddenly have a 'come from behind win.' It's a surprise victory.)

It is too early for the slate to give up even with just 2 weeks left before election day, Pangilinan said.

"Hindi pa tapos ang boxing, ika nga. Ipaglalaban natin ang bawat boto hanggang sa huli," he said.

(The boxing match is not yet over. We will fight for every vote until the end.)

Tañada, meanwhile, was thankful that his voter awareness jumped by 13 percentage points, even if his voter support decreased to 3.6 percent in April from 5.3 percent in March.

"This is the first time I broke 50 percent awareness. I believe that the work we put in after Holy Week will continue to push our trajectory upwards," he told ABS-CBN News.

Aquino, whose voter support dropped by 5 percentage points in the latest survey, thanked his supporters and staff for continued support.

"Salamat po sa mga matatapang at matitiyagang tumutulong sa atin at laging buo ang loob at walang pagod," he said in a statement.

(Thank you to all the brave and relentless supporters who remain dauntless and tireless in helping our campaign.)

Aquino earlier said it would take a "miracle" for the opposition senatorial slate to succeed in the May 13 elections as most of the candidates continued to suffer from low awareness and support in the campaign's final leg.

• Otso Diretso hopes for 'miracle' as campaign hits homestretch

Aside from lack of campaign funds, Otso Diretso is having a hard time climbing survey ranks as the administration's two-pronged slates - PDP-Laban and Hugpong ng Pagbabago - have "crowded out" resources, political analyst Ranjit Rye said.

"These 2 machines have crowded out both supporters, financiers and machinery both at the national and local level," Rye said.

"It's kind of a weird thing. The people who are really fighting against each other [for a Senate post] are from the same coalition. In fact, the competition is not between the administration and the opposition, it's between the two administration parties," he said.

But political analyst Aurelio German echoed Pangilinan's hope that the opposition slate could still pull a surprise win, noting some survey answers are dependent on factors that may change.

"Ang survey, may chance 'yan na hindi makatotohanan. 'Yung mga sinasabi nila, ng mga sagot nila, maraming mga factors 'yan. Maaring natatakot magsabi ng katotohanan," German told DZMM in an earlier interview.

(In surveys, there is a chance that they (respondents) are not telling the truth. Their answers are affected by different factors. They may be scared to tell the truth.)

"Sa atmosphere ng politika ngayon, hindi natin alam, baka ma-riding-in-tandem ako kapag sumagot ako ng mali eh... May fear factor. Ang mga tinatanong sa survey, siyempre they want to be sure of their safety," he said.

(The political atmosphere nowadays, we don't know, you might be hit by riding-in-tandem criminals if you give the wrong answer... There is a fear factor. The survey respondents, of course they want to be sure of their safety.)

• Can Otso Diretso bets pull off surprise win?