Iliana Iotova and Kiril Valchev lead the race for president with 47.3%, ahead of Andrey Gyurov and Georgi Kandev on 30.6%, a national poll by Market Links shows. A runoff is expected because no ticket tops 50% of the vote.

The gap between the top two tickets is 16.7 percentage points. The poll's forecast for the first round gives Iotova and Valchev just under half of the valid votes, with turnout between 37% and 41%. Market Links says Gyurov and Kandev will finish second and go through to the runoff.

Kostadin Kostadinov and Petar Volgin are third. Their result is twice the 10.3% support for Vazrazhdane. Market Links says the relatively high trust in Kostadinov during the campaign is greater than his party's result and points to his potential to win a majority vote. The other tickets are below 5%. Some 3.8% of those who voted say "I don't support anyone". They are not counted in the candidates' shares.

The prime minister's net rating is +1 point in October. It has fallen every month since May, when it stood at +34. Market Links says Rumen Radev is the only leader whose rating is nominally positive.

The poll says the main gauge of how the government is doing is trust in the cabinet, which has been in office for five months. Some 36% say they trust it and 41% do not. The cabinet's net rating is a further 4 points lower than in September, when it was balanced.

Parliament has the trust of 18%, the same as a month earlier. Distrust is 64%, up from 58% in September and 51% in July.

Radan Kanev and Asen Vasilev have a net rating of around -50 points. Distrust of GERB leader Boyko Borisov is 79%. Democratic Bulgaria co-chairs Ivaylo Mirchev and Bozhidar Bozhanov have trust close to Borisov's, but their distrust is substantially different. Delyan Peevski has the lowest net rating, at -85 points. Market Links says the reason is that distrust of him is the highest.

Some 68% of those polled are closer to the view that the attack on commercial ships in the Black Sea is a very serious threat to national security. Another 17% are in the middle of the scale, and 15% are closer to the view that the risks are overstated. More than a quarter think Ukraine itself is behind it. Market Links says opinions on who is responsible lean more towards Russia.

The poll questioned 1,006 people over 18 between 13 and 19 October, by face-to-face interview and an online survey. Market Links funded it together with a media partner.