Former prime ministers, ministers, senior reserve and retired officers, diplomats and public figures have signed a joint declaration backing Andrey Gyurov ahead of the presidential run-off. The names on it include Boyko Borisov, Ivan Kostov, Nikolay Denkov, Rosen Plevneliev and Sofia mayor Vasil Terziev.

The document calls on people to vote for Andrey Gyurov and Georgi Kandev. The signatories say national security must come before party differences, and old disputes must not stop people from seeing a common danger.

The declaration says the president and the government underestimate the threat and are not preparing the country to respond properly. The signatories believe this fails to deter the aggressor and creates conditions for new attacks.

"Allies can make up for a lack of capability, but not for a lack of political will," they write.

They say the authorities refuse to admit the Russian threat, including in Bulgaria's contiguous zone, and refuse to name the Kremlin as responsible for the escalation in the Black Sea. Bulgaria's own capabilities and those of its allies are not used enough, they say, which leaves the country far more exposed. In their view, the effects already hit every person, business, trade and the safety of shipping to and from Bulgarian ports.

"We must not wait for another sunken ship, an attack on infrastructure, a terrorist act or deaths to admit the scale of the risk," the declaration says.

The signatories say that in Bulgaria, Romania is criticised for defending itself and shooting down Russian drones, on the argument that this provokes Russia. They say recent events show the price of the illusion that Putin can be calmed with concessions.

Putin wants NATO to return to its pre-1997 borders and not station forces beyond them. The signatories see this as a push to return Bulgaria and Eastern Europe to Russia's sphere of influence and to take Eastern Europe out of NATO. They say neither Iotova nor Radev has said anything on the issue.

The authors say the public is denied a realistic picture of the danger, because it keeps hearing claims that match the Kremlin's positions and contradict the assessments of the EU and NATO. They appeal to people who see themselves as patriots and defenders of Bulgaria's place among Europe's democracies and in NATO. In the signatories' words, a vote for Gyurov and Kandev is the only real chance to stop a slide into international isolation and a new national disaster. They add that the state needs a counterweight to the policy of Rumen Radev and must not be left without a check at the highest level.

The signatures are in alphabetical order. Plevneliev was president from 2012 to 2017. Former ministers who signed are Anyu Angelov, Atanas Zapryanov, Boyko Noev, Valentin Radev, Velizar Shalamanov, Daniel Mitov, Meglena Kuneva, Korman Ismailov, Nikolay Vassilev, Nikolay Nenchev, Nikolay Svinarov, Rumyana Bachvarova, Todor Tagarev and Traicho Traikov. The military signatories are Lt Gen Dimitar Iliev, Vice Adm Georgi Fidanov, Maj Gen Lyuben Stoykov Pandev, Maj Gen Stefan Dimitrov and Brig Gen Dinko Ivanov. Diplomats and public figures who signed include Valeri Rachev, Vesela Cherneva, Evgenia Koldanova, Iliyan Vassilev, Radan Kanev and Stefan Tafrov.